Compared to what Israel could bring to bear, the United States has more aircraft capable of reaching Iran, our planes would not need to fly through other countries’ airspace, and they can carry much bigger and more powerful weapons. The United States can employ huge, long-range bombers such as the B-52, B-1, and B-2 and a vast fleet of refueling tankers, allowing the bombers to launch from bases in the United States itself, if necessary. America’s ability to operate from the British island of Diego Garcia in the Indian Ocean, however, provides a far more convenient in-theater base. These big bombers can also carry many more bombs and much bigger bombs than anything in the Israeli arsenal, including the 30,000-pound Massive Ordnance Penetrator, which is the only conventional weapon that may be able to destroy Iran’s Fordow enrichment plant. The U.S. Navy still has ten enormous Nimitz-class aircraft carriers, each one of which typically deploys with thirty-six to forty-eight F-18 fighter-bombers and twenty-eight support aircraft. Although three carriers are normally on station around the world at any time, in times of crisis, the Navy can surge four or even five if necessary. Another advantage that the United States has over Israel is a vast fleet of unmanned aerial vehicles (UAVs, or “drones”) and large numbers of air- and sea-launched cruise missiles. The United States has basing rights at airfields in Kuwait, Qatar, and the UAE—and at times has also been able to use facilities in Saudi Arabia, Bahrain, and Oman. If those states allow American aircraft to use their bases, additional wings of American Air Force fighters and strike planes (F-15s, F-16s, F-22s, F-117s, and someday F-35s) can be added to the lineup for an air campaign against Iran.
As a result, the United States could attack far more sites than the Israelis, with much greater certainty that they would be destroyed. Whereas the Israelis probably could go after no more than about six of Iran’s most important nuclear facilities, the United States could attack dozens of other targets: secondary nuclear sites, ballistic missile production plants and bases, leadership targets, even research facilities that support both the nuclear and missile programs.
These forces also give the United States a wide range of options for how to attack Iran. Washington could decide to employ only stealthy forces to effectively eliminate the problem of Iranian air defenses. In such a scenario, the United States would target Iran’s aboveground, unfortified nuclear facilities (like the Esfahan uranium conversion plant and its various centrifuge and ballistic missile manufacturing facilities) with scores of air- and sea-launched cruise missiles launched from B-52 bombers and Navy ships in the Persian Gulf and Arabian Sea. The United States might complement this attack by targeting key leadership sites or small facilities located in populated areas with UAV-fired weapons. Iran’s large and heavily fortified sites—such as Fordow, Natanz, and Parchin—would be left to B-2 bombers carrying bunker-busting munitions including the MOPs. If necessary, the B-2s could even be escorted by stealthy F-22 fighters. Such an operation would be small, perhaps consisting of no more than several hundred cruise missiles, UAVs, and manned aircraft sorties. Conceivably, it might take place all in one night. However, an attack such as this one might only be able to destroy a dozen or more of Iran’s highest-value nuclear and ballistic missile sites, which might not set back Iran’s pursuit of a nuclear weapons capability much more than an Israeli strike would.
If a stripped-down operation can’t do the job, the United States has almost limitless options to go bigger. Larger campaigns would sacrifice stealth for brawn, but could hit many more targets and have a far greater certainty of destroying them. Larger, more comprehensive air campaigns would likely be structured and sequenced somewhat differently from scaled-down versions. In the first wave of sorties, some strikes might be directed against key Iranian nuclear facilities, especially those containing assets believed to be easy for Iran to move. But this type of campaign would likely focus its initial efforts on destroying Iranian air defenses, including radars, surface-to-air missiles, and fighter aircraft, to establish air supremacy. The initial waves would be followed by attacks against Iranian nuclear facilities, ballistic missile production and storage sites, research centers, and leadership targets. American intelligence and reconnaissance aircraft (and satellites) would monitor the attacks to assess damage while follow-on sorties would restrike targets missed the first time. Some targets, such as Natanz and Fordow, might require repeated strikes to ensure that penetrating munitions could “dig” all the way to the centrifuge halls themselves. Some sorties might be directed—or held in reserve—against Iranian air and naval forces along the Strait of Hormuz to prevent them from attempting to close the Strait in retaliation for the American strikes.
A large air campaign would likely involve thousands of sorties and cruise missile attacks, and could last anywhere from several days to several weeks. By way of comparison, Operation Desert Fox—a three-day air campaign against Iraq in 1998 that sought to destroy thirteen purported Iraqi WMD facilities and nearly fifty “regime-protection” and leadership targets—required 650 manned aircraft sorties and 415 cruise missile strikes.10 American aircraft and munitions are more capable today than they were then, and we can rely on UAVs to perform some of the missions for which we once had to use manned aircraft, but Iran’s air and air defense forces are somewhat more formidable than Iraq’s, and the United States might want to destroy more targets than during Desert Fox.
An American air campaign is likely to do more damage to the Iranian nuclear program than an Israeli strike. An American air campaign could potentially do much more damage to the Iranian nuclear program than an Israeli strike, especially if the United States opted to mount a large, sustained operation involving thousands of missiles and air strikes over days or weeks. Beyond that, predictions get murky. Cordesman and Toukan concluded in their study of an American air campaign against Iran that “[d]epending on the forces allocated and duration of air strikes, it is unlikely that an air campaign alone could alone [sic] terminate Iran’s program. The possibility of dispersed facilities complicates any assessment of a potential mission success, making it unclear what the ultimate effect of a strike would be on Iran’s nuclear facilities.”11
As an example of the uncertainties surrounding an American air campaign, the United States believes that the MOP bomb can destroy the Fordow facility, but no one is sure. Repeated strikes on Fordow with MOPs almost certainly would render the facility unusable by collapsing tunnels, sealing entrances, closing off air shafts, and the like. But this would mean hitting the facility with quite a few of these enormous bombs, which can only be carried by the B-2, including restrikes over several days to be certain that the facility was sufficiently damaged.12 The most cogent pro-air-campaign argument yet presented acknowledged that the MOPs might not be able to destroy Fordow, and recommended striking before it was fully operational.13
Then there is the constant problem of secret Iranian facilities. The IAEA and the Western powers are all combing Iran for any sign that Tehran is building secret facilities. This probably makes it less likely that the Iranians are hiding something from us, but we don’t know what we don’t know. We assume that because we have found several secret Iranian facilities, that means that it is unlikely that the Iranians could hide other facilities from us. Yet in almost every case, it took about three years from the time that Iran began work on a secret site to when we discovered it. Are there sites in Iran that they began one, two, or even three years ago that we simply haven’t found yet because they have not reached a stage of completion that we can detect? Are there other sites out there that are near completion or even fully operational that we just never found? Even if we suspect that there aren’t, we cannot be certain, and given our history, we should not be. In the 1980s we found several secret nuclear facilities that the Iraqis tried to hide from us and that too made us confident that we knew where all of Iraq’s hidden nuclear sites were, only to find out in 1991 that we didn’t. Former director of the Central Intelligence Agency Michael Hayden has publicly dismissed the notion of an American (or Israeli) strike on Iran, because he doubts that the United States (or Israel) knows where all the key targets are and he fears that attacking would instead ensure a desperate Iranian push for the bomb.14
Another frustrating uncertainty akin to those of an Israeli air strike is over how fast the Iranians could rebuild from scratch. If an American air attack were wholly successful and wiped out the Iranian nuclear program completely, and the Iranians still decided to rebuild, how long would it take them? The United States can wreck Iran’s centrifuge halls, mangle the centrifuges themselves, obliterate their power sources, and so on, but we can’t remove the knowledge from the heads of their scientists. Most estimates of the degree of Iranian scientific knowledge about enrichment and nuclear weapons indicate that the Iranians have advanced to where they could start from scratch and be back to their current state in somewhere between two and five years, with some willing to go as high as seven. A 2012 report by the Congressional Research Service concluded that Iran could rebuild most of its centrifuge workshops within six months after an attack, after which Iran could start manufacturing replacement centrifuges. The report also warned that neither the United States nor Israel knew for certain where all of Iran’s nuclear facilities were located and therefore that it was “unclear what the ultimate effect of a strike would be on the likelihood of Iran acquiring nuclear weapons.”15 Perhaps for the same reasons, former deputy secretary of defense Colin Kahl has warned, “Senior U.S. defense officials have repeatedly stated that an attack on Iran’s nuclear facilities would stall Tehran’s progress for only a few years.”16
While it is not impossible for the United States to wipe out Iran’s nuclear program completely, especially if Washington were willing to mount a massive, sustained air campaign, it is more likely that even American strikes would not succeed quite to that level. A major American air campaign against Iran would undoubtedly do extensive damage to the Iranian nuclear and ballistic missile programs, but how extensive? If an Israeli strike would be expected to set the Iranian nuclear program back by a year or two, how much longer would an American campaign set it back? Eighteen months? Three years? Five? We do not know.
IMPACT ON IRANIAN POLITICS. Those who oppose air strikes invariably argue that such a campaign would engage Iranian nationalism and latent anti-Americanism and create a “rally ’round the flag effect” that would galvanize the Iranian people to greater support of the regime.17 For instance, then–secretary of defense Leon Panetta, in his remarks at the Saban Forum in December 2011, said that one likely unintended consequence of a military strike on Iran’s nuclear facilities would be that “the regime that is weak now . . . would suddenly be able to reestablish itself, suddenly be able to get support in the region.”18 Those who favor air strikes disagree, insisting that any such impact would be short-lived and would eventually be replaced by deepening popular unhappiness with the regime, because most Iranians would blame the regime for having made the mistakes that provoked the American attack.19 In what is probably the definitive article promoting an Israeli strike on Iran, the cannily iconoclastic Iran expert Reuel Gerecht has charged, “An Israeli strike now—after the rise of the Green Movement and the crackdown on it—is more likely to shake the regime than would have a massive American attack in 2002, when Tehran’s clandestine nuclear program was first revealed. And if anything can jolt the pro-democracy movement forward, contrary to the now passionately accepted conventional wisdom, an Israeli strike against the nuclear sites is it.”20
This debate is of more than passing importance. It is part of the question of whether Iran would reconstitute its nuclear program after American air strikes. There is too little evidence and too many unknowns to be certain, but here is how I add up the evidence. I see three factors that bear on this question.
The first is the general pattern of air campaigns and their impact on the civilian population of the targeted country. The evidence is overwhelming and compelling: when people are bombed by another country, they do not blame their own government for provoking the bombing—they blame the country doing the bombing. From Spain in the 1930s to Germany and Japan in the 1940s, to Vietnam in the 1970s, to Iraq and Iran in the 1980s, and Iraq and Serbia in the 1990s, this pattern has held.21 However, there are some important divergent aspects worth noting. In all of these wars, bombing campaigns directed against the civilian population did help cause the populace to tire of the war. Second, the air campaign against Serbia apparently made Slobodan Milosevic concerned that it was turning the Serbian populace against him, and this fear does appear to have been part of his rationale for conceding Bosnia.22 Third, at least in Iraq, disenchantment with the regime for bringing about the prolonged bombing and sanctions did not bring about any commensurate increase in popularity of the United States. Most Iraqis hated Saddam’s policies and the misfortune they had brought on Iraq, but they also blamed the United States for their misery.23
With regard to Iran specifically, several points are relevant. Many Iranians are strident nationalists who have had it ingrained in them that foreign interference is the root cause of Iran’s problems and therefore that they must resist any and all foreign interference in Iranian affairs. Many Iranian dissidents have shied away from taking money or other support from foreign governments, and Iranian regimes (and even just politicians, dating back to Mosaddeq) try to discredit rivals by branding them as tools of foreign regimes. In addition, the regime easily crushed the Green Movement in 2009—and prevented it from even mounting protests in 2011. This suggests that popular unrest is unlikely to have much impact on the regime regardless of its inspiration, at least unless some dramatic change takes place. At present and for the foreseeable future, there is nothing apparent that will change the regime’s determination to hold power by dint of force whenever it is necessary.24
Based on all this, it seems most likely that American air strikes will make Iranians angry at the United States, but may not have much impact on their feelings about their own government one way or the other. Those Iranians who support the government will hate the United States even more, and those who dislike their government won’t like their government any more, but they probably will like us less. The regime, I suspect, will play up these sentiments to justify whatever it wants to do in the aftermath of an American strike: arrest even more dissidents and political opponents, withdraw from the NPT, demand greater hardships from the Iranian people in the name of combating the United States, and rebuild its nuclear program.
Moreover, based on the historical pattern of air strikes and the history of Iranian nationalism, if this outcome proves wrong, it seems more likely that it will be wrong in the direction of rallying the Iranians to support their government than in the direction of causing Iranians to turn against the regime. It is not that the latter is impossible. Just that the history does not appear to support it as strongly as the other two possibilities. What’s more, even in the best case for the United States, in which our air strikes do rouse the Iranian people to try once again to take action against the regime, I suspect that the regime will be able to crush the unrest once again absent direct, large-scale American military intervention on behalf of the revolutionaries.
WOULD IRAN REBUILD ITS NUCLEAR PROGRAM? As with an Israeli strike on Iran, another critical question is whether the Iranians would try to rebuild after. Here as well, there are some differences from the Israeli case. Proponents of an American strike argue that the fact that the United States had attacked Iran would demonstrate that Washington had the capability and the will to do so, and therefore could do it again in the future. They contend that this would probably convince Iran to give up on its nuclear ambitions altogether, lest it face repeated American air campaigns. Others argue that, contrary to my assessment laid out above, American air strikes will cause such deep internal political problems for the Iranian regime that they will be unable or unwilling to rebuild their nuclear program. These are not foolish ideas. They could be correct.
However, I suspect that they are less likely than those scenarios in which Iran does choose to rebuild its nuclear program. Again, I think it more likely that an American air campaign would either bolster or at least would not further exacerbate the Iranian regime’s relationship with its people. More than that, I expect that the regime would contain any unrest that followed American air strikes. I see the Iranian hardline leadership, particularly Khamene’i, as convinced that the United States is seeking to overthrow him and the whole Islamic Republic. This suggests that American air strikes would only harden his desire to have nuclear weapons to deter another such attack. Finally, I suspect that the Iranians will believe that they could rebuild their nuclear program as long as they evict the IAEA inspectors and act in greater secrecy, employing even greater dispersal and digging even deeper underground wherever possible.
My view seems to echo those who have some insight into this question.25 I have already noted former CIA director Michael Hayden’s conclusion that American (or Israeli) air strikes would doubtless prompt Tehran to rebuild as quickly as it could.26 Likewise, Colin Kahl argues, “By demonstrating the vulnerability of a non-nuclear-armed Iran, a U.S. attack would provide ammunition to hard-liners who argue for acquiring a nuclear deterrent.”27 My remarkable colleague Michael O’Hanlon has surveyed the landscape of expert opinion and reached the same conclusion, writing, “Most U.S. (and Israeli) nuclear experts now think that Tehran is so far along with its nuclear program that it would be able to rebuild the entire program in two years. In this light, a successful air campaign would be a Pyrrhic victory—if even that, given the ambiguity surrounding the exact nature and extent of Iran’s nuclear facilities.”28 Perhaps the best case for an air campaign so far has been made by former Pentagon aide Matthew Kroenig, yet he too worries that air strikes would only delay the Iranians and would not keep them from reconstituting: “Even if the United States managed to eliminate Iran’s nuclear facilities and mitigate the consequences, the effects might not last long. Sure enough, there is no guarantee that an assault would deter Iran from attempting to rebuild its plants; it may even harden Iran’s resolve to acquire nuclear technology as a means of retaliating or protecting itself in the future.”29
Saddam rebuilt (and vastly expanded) his nuclear weapons program after the 1981 Israeli attack on Osirak, and he initially intended to do so again even after the massive destruction of Operation Desert Storm in 1991. In the first years after the Gulf War, he played ridiculous games with the UN inspectors to try to hide those elements of his nuclear program that weren’t destroyed by the coalition air campaign. Indeed, the definitive post-invasion assessment ultimately concluded that right up to the bitter end in 2003, Saddam still planned to rebuild his nuclear program whenever he was able to do so.30 Khamene’i’s Iran is not Saddam’s Iraq, but Tehran’s determination to acquire nuclear weapons (or merely a nuclear weapons capability) and to disregard all manner of sanctions and other hardships to do so appears similar, if not identical.
Recognizing the unknowns, it is still the case that the logic of the circumstances, the historical analogies, and the limited information available all suggest that it is more likely than not that the Iranian regime would try again to build nuclear weapons even after an American air campaign. Of course Khamene’i has every incentive to say so before an attack, but he has indicated that he would continue Iran’s nuclear program under all circumstances, declaring in February 2012, “No obstacles can stop Iran’s nuclear work.” Because of this likelihood, in weighing whether to launch such an air campaign against Iran, the president of the United States would have to assume that the Iranians would reconstitute.
COULD WE USE AN AIR CAMPAIGN TO HELP OVERTHROW THE IRANIAN REGIME? One way to overcome Iran’s determination to revive its nuclear program even after an American air attack would be to go after the regime itself. This is especially appealing to those who believe that air strikes might destabilize the Islamic republic. However, there is still the problem that the regime has consistently demonstrated an overwhelming ability to crush domestic opposition movements, even including the massive 2009 Green revolt. To try to square that circle, some have mused about the possibility of using an air campaign to go beyond destroying Iran’s nuclear program and help the Iranian opposition overthrow the regime. Imagine the Green Revolution all over again, but this time with American airpower intervening to smash the regime’s security forces and allow the opposition to seize power over a carpet of American bombs. The NATO air effort in support of the Libyan rebels in 2011 is the obvious analogy here, but so too is the U.S. air campaign that allowed Afghanistan’s Northern Alliance to evict the Taliban in 2001.
If U.S. air strikes also targeted the regime’s security services, internal command and control network, key transportation choke points, leadership targets, all the while providing on-call fire support for Iranian rebels facing regime security forces, there is some probability that Iranian revolutionaries might defeat the regime’s security forces and gain power. However, doing so would require a massive air campaign on its own, on top of whatever necessary sorties were needed to destroy the Iranian nuclear sites. By way of comparison, during the six weeks of Operation Desert Storm, the coalition air forces flew 38,000 interdiction sorties to cripple Iraqi forces in the Kuwait Theater of Operations that began with more than 500,000 men.31 Although those strikes did tremendous damage to Iraqi forces, key units (principally Saddam’s Republican Guard) still fought fiercely against the overwhelming coalition ground offensive and still retained the strength to crush both the Kurdish and Shi’i revolts that broke out after the end of Operation Desert Storm.32 Thus, an air campaign to enable regime change in Iran would have to do better. Nor does Kosovo provide a more hopeful example. In Kosovo, NATO air forces flew 3,400 interdiction sorties over seventy-eight days against roughly 100,000 Serbian troops, and caused much less damage than against Iraq.33 Those air strikes failed to enable the Kosovo Liberation Army to make any significant headway against Serbian Forces.34 Finally, in Libya in 2011, NATO flew more than 9,700 interdiction sorties over 203 days that helped Libyan rebels defeat 20,000–40,000 Libyan regime troops and paramilitary forces.35 NATO’s success in Libya was largely a function of the incompetence and apathy of Qadhafi’s troops.36 Every one of those campaigns also required thousands more sorties for air superiority, electronic warfare, suppression of enemy air defense, command and control, reconnaissance, and logistics to support the strike sorties.
Historically, victory in these kinds of campaigns hinges on the commitment of the regime’s forces. The more determined they are, the harder it is to defeat them, the more sorties, and the more time it takes to enable opposition ground forces to prevail.37 From what we have seen of Iran’s security forces, there is no reason to believe that they would be unenthusiastic in defense of the regime. Iran’s 150,000-strong Revolutionary Guard can call on hundreds of thousands of Basiji militia to bolster their numbers. Iran’s regular armed forces, the Artesh, have competed for years to prove that they are just as loyal to the regime as the Guards are. And beyond them, the regime can call on tens of thousands of Law Enforcement Force personnel and thugs from Ansar e-Hizballah—paramilitary groups that it uses to beat up and kill Iranian protesters.38
There are many questions to answer to determine how much airpower would be needed to give Iranian rebels a shot at overthrowing the clerical regime: how much of Iran’s security services would have to be defeated, how many cities would be involved, would the morale of the Iranian security services crack, and so on. The United States might need anywhere from a few thousand to tens of thousands of sorties and, as in Iraq and Kosovo, even that might not be enough. Cracking the morale of enemy ground forces (let alone destroying them physically) by airpower alone is a very difficult undertaking, requiring repeated applications of force over many days. Never have small doses of airpower broken an enemy army by itself. And incorporating this mission into an air campaign meant to knock out Iran’s nuclear program would be adding a massive additional undertaking; one that runs contrary to the whole point of a policy option meant to destroy Iran’s nuclear facilities and disengage to avoid a wider war with Iran. Trying to use airpower to assist a revolution against the Iranian leadership would produce that wider war. If the United States were looking to overthrow Iran’s government by force, it would be better to do the job right by invading with ground forces rather than gamble on airpower alone.
As always when discussing American air campaigns, the military dimensions make the idea seem easy, straightforward, and entirely under our control. But of course, as Carl von Clausewitz warned two centuries ago, that is never the case in war because “everything in war is very simple, but the simplest thing is difficult.”39 Nothing about Iran is easy or straightforward and there are many potential complications to an American air campaign against Iran to eliminate its nuclear sites.
The reaction of other peoples and governments to an American strike could be particularly important and difficult to manage. Although the United States might not face the same degree of international outrage as Israel for attacking Iran’s nuclear program, in many scenarios, we would incur considerable ill-will. That would be more problematic for the United States because of our greater reliance on international cooperation, both against Iran and around the world.
INTERNATIONAL LAW. For some people, international law is sacrosanct. They believe that it would be much better to live in a world of laws than an anarchical international order where might often makes right. Or they believe that the United States benefits from the current system of international law, and therefore the U.S. should not undermine it. For others, however, international law is worse than irrelevant: it is something that the powerless use to constrain the powerful. They tend to regard advocates of international law as dangerous dreamers who would hamstring the United States in pursuit of a utopian will-o’-the-wisp. In the case of air strikes against Iran, indeed any military action against Iran, there are reasons why both groups need to pay attention to international law.
The basic problem is that absent an Iranian provocation, it will be hard for the United States to justify using force against Iran. Since the 1990–91 Persian Gulf War, the United States has typically relied on UN Security Council resolutions to justify force. There have been a few exceptions. For Operation Enduring Freedom, the 2001 campaign against Afghanistan, the United States invoked the right to self-defense under Article 51 of the UN Charter in response to the 9/11 attacks. In Kosovo in 1999, NATO had no legal basis for intervention and some legal scholars branded the war illegal. What mattered, however, was that all of the NATO nations, all of the EU countries, and many other countries ultimately supported the intervention—indeed, then UN secretary-general Kofi Annan asserted that the war was “legitimate” even if the absence of Security Council authorization did not necessarily make it “legal.”40 Interestingly, the United States had a far stronger legal basis for the 2003 invasion of Iraq, resting on the UN Security Council resolutions from 1990–91 authorizing the use of force to ensure Saddam Husayn’s compliance with all of the conditions imposed by the UN after the Persian Gulf War. Yet the invasion of Iraq was denounced in many quarters as illegal. Arguably, the problem in this case was the opposite of Annan’s remark about Kosovo: whereas that campaign may have been illegal but legitimate, the Iraq War was legal but eventually seen by many as illegitimate.
An attack on Iran could fall on the wrong side of both the Kosovo and Iraq experiences. Since 2006, there have been six UN Security Council resolutions against Iran enacted under Chapter VII of the UN Charter. However, every one of these resolutions has noted that it does not authorize the use of force. This assertion is not accidental: it was demanded by Russia and China (and others) as a condition for their voting in favor of the resolutions. Many Americans oppose the use of force (a topic addressed in greater detail below). Even America’s European allies have drawn stark lines between supporting sanctions and supporting military operations.41 Unless Iran does something stupid that constitutes an unquestionable casus belli, it is unlikely that the Chinese and Russians would allow a new resolution authorizing the use of force to pass the Security Council.
The legacy of the Iraq War is part of the issue and a major impediment to winning over international support for an attack on Iran. Absent an inexcusable Iranian provocation, an American attack would probably look to many like a replay of the Iraq War. The United States and its allies will have been claiming that Iran is developing weapons of mass destruction, specifically nuclear weapons, while the Iranians—like the Iraqis before them—will be denying it. The Iranians will continue to argue that their nuclear program is for peaceful civilian purposes, and despite the evidence against that, many people will believe it. If the United States attacks anyway, justifying the strike by resort to the UN Charter’s right to self-defense, many will brand it illegal—and they will be on much firmer ground than those who insisted that the Iraq War was illegal. Some respected American legal scholars have already rendered opinions that such an attack would be unlawful.42 In one widely cited law review article, Mary Ellen O’Connell and Maria Alevras-Chen declared, “The law governing the use of force is found in the United Nations (UN) Charter, in customary international law, and in the general principles of law. . . . Under these rules, no use of military force can be justified against Iran for carrying out nuclear research.”43
Some international legal experts have argued that Iran’s nuclear facilities are not materially different from those of Japan, and therefore are barred from attack by an IAEA General Conference resolution. Others will dispute whether those resolutions have the force of law, or whether there are material distinctions with Japan’s nuclear program.44 The International Court of Justice has gone so far as to assert that violations of the NPT and even acquisition of nuclear weapons themselves would not, on their own, constitute a violation of the UN Charter or international law justifying the use of force.45 Of course, Iran’s own claims that the UN sanctions are somehow illegal have been repeatedly refuted, but that does not furnish a legal basis for an attack.46 What is clear is that making a legal case for going to war against Iran would be much, much harder than going to war against Iraq in 2003. In the words of John Bellinger and Jeff Smith, two legal scholars who have both wrestled with these issues as general counsels of the State Department and CIA, respectively, “In the absence of U.N. authorization, many nations, including some of our allies, are likely to believe that a pre-emptive attack (on Iran) would violate international law.”47
For some Americans, this legal prohibition alone might be enough to oppose an attack on Iran. For others, the issue is more practical. The lack of a clear legal basis will make an operation that is going to be hard enough to pull off politically and diplomatically that much harder. Matt Waxman, who fought the legal trespasses of some of his more zealous colleagues in the Bush 43 administration, worries that in the case of Iran, “Dubious legality makes military action more costly—including in terms of military, political, and diplomatic repercussions, as well as long-term precedent that may be exploited by others—and therefore affects its perceived merits relative to other options.”48
If the president of the United States ever has to take to the airwaves to announce that we have attacked Iran to prevent it from making any further progress toward a nuclear weapons capability, he or she could have a hard time justifying the legality of an attack. That would make a hard political and diplomatic sell even harder. A September 2012 report signed by thirty-five distinguished former national security officials, generals, and experts on Iran warned that “if the U.S. and/or Israel end up attacking Iran’s nuclear program without [an international] mandate, hard-won international support for maintaining sanctions against Iran could be substantially weakened. China and Russia would loudly condemn military actions against Iran, and some European nations might pull back from a sanctions regime after such attacks. Iran would be seen by many around the world, Muslims and non-Muslims alike, as the victim of unjustified American and/or Israeli military action.”49 Thus, even if you don’t regard international law as meaningful in and of itself, in the case of military operations against Iran, international law will play a role—and potentially a significant one—in determining international support for America’s actions.
As a final point on this topic, there are some smart, well-meaning people who have suggested that the United States might not acknowledge an attack on Iran, just as Israel has never acknowledged its attacks on the Syrian nuclear reactor at al-Kibar, an arms factory in Khartoum, and other sites.50 This idea is beyond far-fetched. The United States of America isn’t the state of Israel. The only time that the United States tried to conduct a massive bombing campaign unacknowledged was Nixon’s secret bombing of Cambodia in 1969–70, and that ended badly for all involved. If the United States launches an air campaign against Iran, it is going to become known immediately and the American people are going to demand an explanation—and the president is going to have to give it to them. This attack will not be a drone strike against an al-Qa’ida terrorist isolated in the mountains of Yemen or Pakistan, where the governments have granted the United States permission to conduct such strikes.51 It will be a major military operation, an act of war against a sovereign government, that will result in Iranian and American casualties, especially as a result of Iranian retaliatory acts. Every American will want to understand why the president thought it necessary, what the U.S. government hopes to achieve, how the U.S. armed forces will try to accomplish these goals, and what to expect in the future. The Congress will (rightly) demand an explanation, if not its blessing. A campaign on this scale is not something any president can ignore or cover up, nor could I imagine that any would want to do so.
BASES. There are several reasons why international support will be important to a U.S. military campaign against Iran. First off, it would be extremely helpful for the United States to be able to use foreign bases near Iran. The United States has Air Force units routinely deployed in Kuwait, Qatar, and the UAE, and has also used facilities in Turkey, Bahrain, Saudi Arabia, and Oman on previous occasions for military operations in the area. The U.S. military would also love to have access to bases in Central Asia and the Caucasus for an air campaign against Iran. Of course, we can only use those bases with the permission of the host governments. Because of the capabilities of U.S. military forces, not being able to use those bases would not be a showstopper: American planes flying from the continental United States, from Diego Garcia, and from carriers in the Gulf and the North Arabian Sea, along with cruise missiles fired from ships at sea, could handle the job alone. However, it would be much more work for them to do so. It might mean limiting the number of targets struck, accepting lesser levels of destruction, or drawing out an air campaign for much longer than would otherwise be necessary.
The problem is that while the GCC, Central Asian, and Caucasus states are America’s friends and allies, they have not always allowed the United States to use those bases. In 1996, the Saudis, the Turks, the Jordanians, and the Kuwaitis did not allow the United States to fly aircraft from their bases in response to Saddam’s attack on the Kurdish city of Irbil.52 For Operation Desert Fox in 1998, the problems got worse: Saudi Arabia refused to allow the United States to fly combat aircraft from its bases, impeding the execution of the plan.53 Similarly, for the 2003 invasion of Iraq, Saudi Arabia refused to allow the United States to fly combat aircraft from its bases, although it did permit support planes to do so.54 Turkey denied the United States altogether in 2003.55 And the reaction of Central Asian and Caucasus states is even more unpredictable. Thus, the more international support for an air campaign against Iran, the more likely that the United States will have access to regional bases, easing the planning, operational, and logistical requirements of an attack.
THE DAY AFTER. If an American air campaign lacked widespread international support, it could incur the same post-strike problems as an Israeli military operation. In the worst case, Iran might garner widespread sympathy and be able to withdraw from the NPT and evict the IAEA inspectors without facing any serious consequences. Many countries, potentially including Russia, China, India, Brazil, and other major powers, might condemn the American attack and begin to ignore the UN-imposed sanctions as they did with Iraq in the late 1990s. The ability of the United States to prevent Iran from reconstituting its nuclear program would be diminished, calling into question the utility of the strike in the first place.
Such an outcome is hardly impossible; in fact it may be the most likely course of events given the current state of international sentiment. The Russians continue to insist that there is no basis for an attack on Iran because there is no reason to believe that the Iranian nuclear program has any military component.56 Russian foreign minister Sergei Lavrov declared in January 2013, “Attempts to prepare and implement strikes on Iranian nuclear facilities and on its infrastructure as a whole are a very, very dangerous idea. We hope these ideas will not come to fruition.”57 In late November 2012, after the IAEA stated that it was becoming worried about a possible military dimension to Iran’s nuclear program and published an extensive dossier outlining its concerns, Russian deputy foreign minister Sergei Ryabkov responded, “We, as before, see no signs that there is a military dimension to Iran’s nuclear program. No signs.”58 The Chinese have stuck to more realistic concerns about the dangers of war to signal their opposition. Chen Xiaodong, head of the Chinese Foreign Ministry’s West Asian and North African affairs division, cautioned in April 2012, “If force is used on Iran, it will certainly incur retaliation, cause an even greater military clash, worsen turmoil in the region, threaten the security of the Strait of Hormuz and other strategic passages, drive up global oil prices and strike a blow at the world economic recovery. . . . There may be 10,000 reasons to go to war but you cannot remedy the terrible consequences of plunging the people into misery and suffering and the collapse of society and the economy caused by the flames of war. . . . The international community has a responsibility to restrain itself from war.”59 Brazil, India, and Turkey also oppose an attack on Iran by either Israel or the United States.60
As for America’s Arab allies, their views are more complicated. At least in private, many Gulf leaders have urged the United States to attack. The New York Times reports that the WikiLeaks cables showed that America’s Arab allies privately “clamored for strong action—by someone else,” but “they seemed deeply conflicted about how to deal with it—diplomacy, covert action or force.”61 King Abdallah of Saudi Arabia is reportedly a staunch advocate of an American attack on Iran, as is Muhammad bin Zayed, the crown prince of the UAE and possibly the most intellectually formidable of all of the Arab leaders.62 Nevertheless, the Gulf leaders demur from openly backing a military operation against Iran.63 Meanwhile, other Arab leaders have opposed it. In 2007, then Arab League chief Amr Moussa and then IAEA chief Mohamed ElBaradei (both now leading Egyptian politicians) both denounced the idea of an attack on Iran, with ElBaradei calling it “an act of madness.”64 Likewise, in November 2011, Prince Turki al-Faisal, former Saudi intelligence chief and former Saudi ambassador to Washington, said of a military attack on the Iranian nuclear program, “Such an act I think would be foolish and to undertake it I think would be tragic. . . . If anything it will only make the Iranians more determined to produce an atomic bomb. It will rally support for the government among the population, and it will not end the program. It will merely delay it if anything. . . . An attack on Iran I think will have catastrophic consequences . . . the retaliation by Iran will be worldwide.”65 And Qatar’s minister of state for foreign affairs, Khalid bin Mohamed al-Attiyah, said an attack on Iran “is not a solution, and tightening the embargo on Iran will make the scenario worse.”66
The potential for air strikes on Iran to send oil prices soaring is part of the opposition to an American (or Israeli) attack on Iran, and how this plays out in the event of an actual conflict will affect international reaction to the attacker. Ultimately, there is no way to predict what will happen to oil prices. It will depend on how the Iranians retaliate. The more they threaten the Strait of Hormuz and demonstrate a capacity to disrupt tanker traffic, the higher oil prices will climb. One sober analysis from 2012 that seems neither to underplay nor to exaggerate the potential impact on oil prices concluded that a strike on Iran’s nuclear program could cause an immediate price increase of about $23 per barrel. This could be expected either to drop to about $11 extra per barrel in the case of a short disruption, or climb to as much as $61 more per barrel in the event of a sustained disruption, depending on how much of international oil reserves were released.67
So there is a real prospect that an American air campaign against Iran would encounter widespread international opposition, and this opposition could cripple the sanctions, inspections, and other measures currently hamstringing Iran’s nuclear progress, all of which would be crucial after a strike to impede or prevent Iran from rebuilding.
Some have argued that even if the Iranians were to rebuild, the United States could just attack again. This idea strikes me as infeasible and improbable. The only time that the United States has been willing to do something like that was against Iraq in the 1990s, when we repeatedly struck Iraqi targets to enforce compliance with the UN resolutions and no-fly zones. Within a few years (probably by 1996 and unquestionably by 1998), however, the international community had tired of these constant strikes and turned against them. Once that happened, even our most enthusiastic Arab allies found it increasingly difficult to support such operations.
In every other conflict—in Iraq in 1991, in Kosovo in 1999, and again in Iraq in 2003—when air strikes alone could not do the job and the adversary resumed its course, the United States felt it had no choice but to escalate to a ground invasion (one that fortunately proved unnecessary in the end in Bosnia and Kosovo). It is understandable that Washington would act this way. The president of the United States cannot be seen as clinging to ineffectual military operations. If airpower does not eliminate the Iranian nuclear program for all time the first time, the president will face tremendous pressure to escalate to a much greater level of force to get the job done. When the American people are roused to war, they want to see it won as quickly as possible to minimize casualties and other costs, and so that they can go back to peace. Repeatedly going to war with Iran is something that the United States simply cannot sustain.
The best way to build international support for an air campaign is old-fashioned diplomacy.
The two Bush administrations together furnish us with everything we need to understand how to build diplomatic support for a war with a Middle Eastern state believed to be trying to acquire weapons of mass destruction. The Bush 41 administration did everything right in fashioning a coalition to evict Saddam from Kuwait in 1991. The Bush 43 administration did everything wrong in its rush to topple Saddam from power in 2003. Between what the Bush 41 administration did and what the Bush 43 administration did not do, we have an excellent blueprint for how to secure international support for a war against Iran. The most important lessons include:
1. Take your time. Going slow is important to demonstrate that the United States is not rushing to war. The United States does not have forever. It would have to attack before Iran acquired a workable nuclear weapon—not just adequate fissile material, a canard that gets bandied about. However, even the worst-case estimates indicate that the United States has at least one to three years before Iran would be able to do so from a decision to start—a decision that has not been given, as best we can tell. If these estimates are inaccurate or the Iranians stick with a breakout capability, as many expect, Washington will have even more time. Using that time for diplomacy would be vital to demonstrate that the United States had exhausted all the alternatives and given Iran every opportunity to solve the impasse.
2. Make Iran a great offer. If the United States is going to convince other countries to support a military operation, it will have to convince them that it was willing to take “yes” for an answer and the Iranian regime wasn’t. That would mean putting a deal on the table that the entire international community would see as a great deal for Iran if it were only seeking nuclear energy, and so other countries would also see no reason for Iran not to accept it. Dennis Ross, President Obama’s former chief Iran advisor, and Iran expert Patrick Clawson—with whom I agree on almost nothing—have both made this suggestion, and they are right that it is necessary to do so to build international support before the United States could even consider military operations.68
3. Enlist others to help improve the offer and help convince Iran to accept it. Russia and China, Turkey and Brazil, India and others all need to be a part of the process. The United States should ask them to help fashion the deal, take their advice, and encourage them to speak to the Iranians. Once the deal has been crafted, these same countries need to be encouraged to convince Iran to accept it, and be given the time to do so. They can’t take forever, but the time limits would need to be measured in months, not weeks, let alone days. Everyone must believe that the United States gave peace every chance and turned to war only when there was no other choice.
4. Go all the way. Any offer to Iran cannot give the Iranians everything they want. However, the United States can and should go much further than it has. The United States needs to give the Iranians what they want related to civilian nuclear power (and throw in some incentives to make it easier to build nuclear power plants), to be ready to accept limited Iranian enrichment, and to prepare to rely on inspections and monitoring to prevent an Iranian breakout.
AN ULTIMATUM, NOT A NEGOTIATION. A critical difference between this approach and what we have done so far is that if the United States decided that it was ready to go to war, it should handle the negotiations with Iran differently from the past. In the talks so far, the United States has assumed that there would be a protracted negotiation between Tehran and the P-5+1, and the United States would be expected to make gradual concessions in return for the same. Consequently, the United States has resisted making any major concessions up front for fear that Tehran would “pocket” them and demand additional compromises during the negotiations. This concern was reasonable, but has proven self-defeating. The United States has been willing to put so little on the table that the Iranians have seen no point even in negotiating seriously. If the United States is ready to go to war with Iran, the talks need to be conducted in a wholly different manner: the offer needs to be an ultimatum, not a bargaining position.
However, for the United States to deliver an ultimatum to Iran that would be accepted as a legitimate casus belli by other countries, that ultimatum will have to pass their muster. The Russians and Chinese in particular will not support a war against Iran if the ultimatum presented to Iran does not appear reasonable to them.
TWO CONUNDRUMS. If four paradoxes would confound an Israeli strike, building the diplomatic support for an American strike faces two conundrums of its own. To gain international support, the United States would have to present Iran with an ultimatum that Russia, China, Brazil, India, and other major countries who oppose war with Iran would see as “acceptable” to Iran. However, at least some of those countries (starting with Russia) so oppose a war with Iran that they will probably declare unacceptable any offer the United States makes in the form of an ultimatum, to try to deny Washington international legitimacy for a strike.
This problem is daunting, but it may not be insurmountable. The United States should be able to work with other countries such as China, India, and Turkey to craft a proposal that should meet Iran’s legitimate needs. If Russia continues to object, it could block action in the Security Council, but would not necessarily deny the operation informal international legitimacy. During the conflict in Kosovo, the Russians similarly opposed a war against Serbia so vehemently that they blocked all action in the Security Council, but the United States and its allies handled themselves so well (and Milosevic so badly) that NATO garnered widespread support for the operation even without a UN Security Council resolution.
The second conundrum for the United States is that Iran might accept the terms of an ultimatum, and if they did so, the United States would have to accept it as well and call off the war. An ultimatum to Iran should look something much like the deal proposed in chapter 6, as the ultimate goal of a carrot-and-stick approach: Iran would be allowed to have civilian nuclear power, would be allowed to enrich uranium up to 5 percent purity, would be allowed a limited number of centrifuge plants and centrifuges, and would be allowed to have a small stockpile of LEU, in return for forswearing any enrichment and stockpiles beyond that, and accepting intrusive and comprehensive monitoring and inspections.
As was the case with the carrot-and-stick approach, whether one is willing to accept that deal determines whether this is a problem or not. For someone like me, who is willing to accept containment over war, this situation is win-win: Iran accepts a deal that would curtail its nuclear activities as well as forcing it to accept intrusive inspections and the United States does not have to go to war. However, many who favor air strikes do so because they would not accept such a deal. Either they believe that Iran would cheat and get away with it, like North Korea, or they do not want to leave Iran with even a latent, long-term breakout capability. For them, air strikes are preferable to a deal. But the problem is that the only way to get international support that could make air strikes successful comes at the cost of having to accept such a deal if the Iranians will.
I do not see a good way around this second conundrum. If the United States does not offer Iran a reasonable ultimatum, it will not have international support for war. Instead, we will face the same kind of situation as in 2003. Like then, it won’t matter much for the opening act, the takedown, but it could prove fatal in the crucial succeeding acts, the follow-through. As has often been our mistake, the United States might win the “war” and lose the “peace,” and the latter matters far more than the former.69
DOMESTIC SUPPORT. Another challenge for an American president seeking to employ air strikes against the Iranian nuclear program will be generating domestic support here in America. So far, the American people have shown little eagerness for military operations against Iran. President Obama and his political advisors made their perception of American war-weariness a critical theme of the president’s 2008 and 2012 electoral campaigns, and one of the few remarks in the president’s second inaugural address related to foreign policy was Obama’s pronouncement, “A decade of war is now ending.”70
Polls of the American public have demonstrated a schizophrenic reaction to war with Iran. Polls that ask a simple binary question—some version of “If Iran is close to developing a nuclear weapon, should the United States use force against it?”—have typically shown results that have varied from a strong majority in favor of war to a strong majority opposed. A March 2012 survey conducted by Reuters-IPSOS found that respondents favored a military strike against Iran 56 to 39 percent if Iran were developing nuclear weapons.71 The Foreign Policy Institute’s 2012 National Survey, conducted in September 2012, showed 62 percent of respondents favored military action to prevent Iran from getting nuclear weapons against only 23 percent who opposed it.72 A Fox News survey from October 2012 concluded that 63 percent of Americans supported the United States taking military action to keep Iran from getting nuclear weapons, and only 27 percent opposed it.73 In contrast, the 2012 Chicago Council on Global Affairs annual survey found that Americans opposed even a UN-sanctioned attack on Iran by 51 to 45 percent, while 70 percent of respondents opposed a unilateral American attack on Iran’s nuclear program.74 In October 2012, a CBS News/New York Times poll found that only 20 percent of Americans felt that Iran was “a threat to the United States that requires military action now,” compared with 55 percent who felt that it could be contained by diplomacy now, and another 16 percent who felt that it was not a threat at all.75
However, whenever Americans have been asked to choose among a variety of ways that the United States could respond to Iran nearing the acquisition of a nuclear weapon, only a small minority favor the use of force, while a much larger majority oppose it. Only 17 percent of respondents to a January 2012 survey by the Princeton Survey Research Associates International backed an air campaign against Iran’s nuclear sites if sanctions proved inadequate. This number compared to 47 percent who supported increased sanctions and 13 percent who favored more aggressive covert action.76 Likewise, a February 2012 NBC News/Wall Street Journal poll asked respondents how the United States should respond if Iran’s nuclear program got “close to developing a nuclear weapon.” Only 21 percent felt that the United States should “take direct military action,” compared to 75 percent who opposed direct military action, although some of these favored other courses of action (supporting an Israeli strike, or more diplomatic and economic actions).77 A CNN/ORC International poll from the same period found that only 17 percent of Americans wanted the United States to use force against Iran to “shut down” its nuclear program, with 60 percent arguing that diplomatic or economic action was the right response, and 22 percent saying no action should be taken at that time.78
This mixed bag suggests that while a determined president could mobilize the American people to act against Iran if he were determined to do so, he might find that support fragile. The Bush 41 administration concluded that it was critical to demonstrate strong international support for evicting Saddam’s army from Kuwait to build domestic support for the Gulf War. So too might a president need to show the American people that much of the world agreed with us and was ready to help us in a fight with Iran, to gain the kind of domestic political support that he or she would undoubtedly want before launching military operations against Iran. And it is always important to keep in mind that in March 2003 most Americans backed the invasion of Iraq.
It isn’t inevitable that Iran would lash out in response to an American air campaign, but no American president should assume that it would not. Iran hasn’t always retaliated for American attacks against it. After the destruction of Pan Am Flight 103 in December 1988, many believed that this act of terror was Iranian retaliation for the shooting down of Iran Air Flight 455 by the American cruiser USS Vincennes in July of that year. All of the evidence now points to Libya as the culprit, which if true would suggest that Iran never did retaliate for its loss. Nor did Iran retaliate for America’s Operation Praying Mantis in 1988, which resulted in the sinking of a number of Iran’s major warships. It is possible that Iran would simply choose to play the victim if attacked by the United States, assuming that this gambit would win the clerical regime international sympathy. Iran might decide that withdrawing from the NPT, evicting the inspectors, and rebuilding its nuclear program would be retaliation enough.
Nevertheless, it seems more likely that Iran would fight back as best it could. The Iranians have threatened to hit pretty much everything in the region that the United States might value even a little: American bases, Israel, Turkey, Saudi Arabia, and any other country that provided assistance to the United States for the operation.79 Khamene’i has repeatedly threatened heavy responses to any American or Israeli attack, and so Tehran might feel compelled to retaliate or else lose any ability to deter subsequent attacks.80
The quickest and most direct response that Tehran could employ would be to lob ballistic missiles at U.S. bases, oil facilities, and other high-value targets located in the Gulf states, Israel, or other U.S. allies. Iran probably has several hundred ballistic missiles that could be used for this purpose, but they are inaccurate and unlikely to do much damage unless directed at cities. Nevertheless, this contingency could drive up oil prices and would still require the United States to deploy considerable antiballistic missile defense assets in the region and provide as much warning to U.S. allies as possible.
Because many Iranian leaders would look to emerge from the fighting in as advantageous a strategic position as possible, they might refrain from any direct retaliatory actions. As Kroenig explains, “Tehran would certainly feel like it needed to respond to a U.S. attack, in order to reestablish deterrence and save face domestically. But it would also likely seek to calibrate its actions to avoid starting a conflict that could lead to the destruction of its military or the regime itself.”81 Thus Iran might keep such missile attacks small and limited, and might refrain from targeting sensitive sites such as the Saudi oil fields, because any damage to them might provoke an even greater American response—and in that case, potentially with widespread international support.
Iran would almost certainly seek to convince Hizballah, Hamas, PIJ, or its other proxies and allies in the Levant to attack Israel with rockets, missiles, mortars, and any other weaponry on hand.82 From Iran’s perspective there would be little to lose and much to gain. Because Israel’s ability to strike directly at Iran is limited (especially compared to the damage that the United States would have just inflicted on Iran), Tehran might have little to fear. Indeed, Israel’s most likely and most powerful responses would be directed against the attackers themselves and the Iranians are probably more than willing to fight to the last Palestinian or Lebanese. However, by attacking Israel, Iran and its allies might be able to stir Arab and Muslim public opinion, possibly even painting the conflict as a new Arab-Israeli or Muslim-Israeli war. That may be a long shot, but given the limited downside for Tehran, why wouldn’t they try? Indeed, most Israeli experts expect that they will.83
All that said, by far the most likely methods of Iranian retaliation would be covert: cyberwarfare and terrorist attack. Such responses could be immediate and coincident with a U.S. air campaign. Iran is believed to have extensive contingency plans for attacks on American targets, and it might be possible for Tehran to execute some terrorist operations in days and cyberattacks in hours. The U.S. intelligence community took the Arbabsiar case as proof that Iran is now willing to conduct terrorist attacks on American soil and believes that Iran is readying more such attacks to respond to an American military action.84
Iranian covert retaliation might also come well after the fact. If Tehran wanted to retaliate in spectacular fashion, especially on American soil, it might take longer to arrange. Major terrorist operations require extensive planning and preparatory work, and they have been especially difficult to execute in the United States ever since the security improvements that followed 9/11. Likewise, Iran might have to develop a more deliberate and complex cyberattack to get past U.S. defenses and cause significant harm to a significant American target or network. At a minimum, the United States would have to take steps to secure and harden U.S. targets against possible Iranian retaliation by cyber or terrorist attack and even then they might not prove fully effective.
Iranian terrorist and cyber attacks might also target America’s allies, particularly those Iran might be looking for an excuse to attack anyway. Iran might try to stir up trouble against the governments of U.S. allies in the Gulf, especially Bahrain, Kuwait, and Saudi Arabia, all of whom have large Shi’i populations in which Iranian intelligence services have made significant inroads. Iran has attempted to overthrow all of these governments in the past, and they might be tempted to do so again.85
WOULD IRAN ATTACK THE STRAIT OF HORMUZ THIS TIME? It is somewhat more likely that the Iranians would attempt to disrupt traffic in the Strait of Hormuz in response to an American air campaign than an Israeli operation. At an obvious level, the Iranians have threatened to close the Strait in response to an American attack and might feel the need to demonstrate that they meant what they said. In a 2012 crisis simulation we ran at Brookings’s Saban Center, the Iran team saw restoring its deterrent as a compelling motive for Tehran and ordered limited mining and harassment of U.S. naval forces in the Strait. In the game, both of these actions got out of hand and provoked the United States to mount a massive military campaign to obliterate Iranian naval and air forces along the Strait of Hormuz littoral.86 Of course, the Iranians have also threatened to close the Strait if the West imposes new sanctions on Iran, and they have never made good on those threats, suggesting that the actual Iranian leadership may behave more cautiously than our Iran team in the simulation.87
Uncertainty is another factor that might push Tehran to move against the Strait of Hormuz. In most cases, if the United States decided to attack Iran’s nuclear sites it would go for a bigger, longer campaign to ensure the maximum damage. In these scenarios, the United States would probably begin by building up its air, naval, and ground forces. This buildup, which might be fairly brief, would be followed by an initial wave of strikes against air defenses, key command and control facilities, and some leadership targets, to create a permissive environment for the strikes against the nuclear facilities. This sequence of events is effectively identical to how the United States would mount either a decapitating air strike against the leadership or start a full-scale invasion. Thus the Iranians could not assume that a limited American buildup meant only limited American military objectives.
In addition, because Iran’s command and control network is old and imperfect, Tehran might be too confused by the initial American attacks to glean precise information about Washington’s intentions. The Iranian leadership may only know that the United States is flying lots of strike sorties against it and is destroying a wide variety of important targets. In either of these circumstances, the regime might decide that it cannot afford to be wrong if it is a U.S. invasion, and might order a defensive closing of the Strait to try to prevent it.
Nevertheless, closing the Strait would hardly be an automatic response for Tehran. Iran’s nuclear program is not the regime’s highest priority, even if it is high on that list. They value their lives and their control of Iran even more. They also care a great deal about their oil production and export facilities, since those are the lifeblood of the Iranian economy and their own personal wealth. There is also their conventional military power, particularly their ability to threaten the Strait of Hormuz, which effectively constitutes their only economic and strategic leverage over other countries. All of these assets would also be vulnerable to American attack. The Iranians would hopefully recognize that they have even more to lose if they provoke the United States to escalate further, particularly by threatening the world’s oil lifeline through the Strait of Hormuz—as long as they can recognize that the United States is discriminating among these target sets.88
Moreover, as discussed in the previous chapter, while Iran might be able to close the Strait for a limited period, American air and naval assets should be able to reopen it in a matter of weeks or months.89 In so doing, the United States would probably cause enormous damage to Iran’s air-, sea-, and ground-based military assets in the area. Iran has spent huge sums to build up these forces over the past two decades, and they are far too valuable to Iran as latent threats with which to manipulate the oil market to risk losing them by closing the strait.
If the Iranians did move against the Strait and closed it for some period of time, the damage they could do to the global economy could be significant albeit short-lived. At present, about 17 million barrels per day (bpd) flow through the Strait of Hormuz, amounting to 35 percent of global seaborne traded oil.90 If that oil cannot be exported through the Strait, there is no way to replace it by producing more elsewhere, as virtually all of the world’s spare oil production capacity is located in the Gulf countries.91 About 2.5 million bpd could be rerouted through pipelines across Saudi Arabia and the UAE, but the 14.5 million bpd that would still be trapped by the closure of the Strait amounts to more than 16 percent of global oil consumption.92 In theory, the strategic oil reserves of developed nations could make up for the loss of 14.5 million barrels per day, and could do so for about one hundred days.93 (There are also private stocks of oil held by companies, but these fluctuate markedly. Thus, while they would certainly help, and potentially a lot, it is hard to calculate by how much.) Nevertheless, if strategic reserves cannot be released with efficiency and speed (and releases have typically proven slower than projected), the price of oil could rise significantly. Likewise, if the Strait were closed for more than three to five months, prices would rise as well. Meanwhile, eleven of twelve major American postwar recessions were preceded by a jump in oil prices.94
Many people believe that it would be possible for the United States to mount limited air strikes against the Iranian nuclear program without having to commit to a wider war, or an invasion of Iran. This is one of the most important arguments in favor of air strikes. While I think this is possible, I think it much less likely than its proponents believe. I see a considerable risk, even a likelihood, that it would not be possible to do so.
There are several dynamics at work that make it fairly likely that air strikes against the Iranian nuclear program would be the start of a much larger U.S.-Iranian war, one that could well push us into an invasion of Iran. That is a big statement. It means that what seems like a major undertaking by the United States itself—several hundred or several thousand air and missile sorties against Iranian nuclear and air defense sites over the course of days or weeks—could morph into a truly massive American ground invasion of Iran requiring several hundred thousand ground troops occupying the country for years or even decades. Yet wars are always inherently unpredictable and often turn out much worse than their authors intended, especially when the instigators do not prepare for it to go badly.
First, there is the likelihood of Iranian retaliation. We don’t know what the Iranians will do, how effective their retaliation will be, or how effective our defenses will prove. The available evidence indicates that they will retaliate, they will want to inflict significant pain, and that they have a reasonable capability to do so—primarily by terrorist and cyberattack. If Iran is able to hit us or our allies hard, there will be significant pressure on the United States to respond, especially if Iran is not content with a few retaliatory shots but continues to wage asymmetric campaigns (terrorism, cyberwarfare, periodic missile and rocket attacks) for weeks, months, even years—all of which it is capable of doing and has threatened to do. Moreover, if any such attacks were to cause major loss of life, or if the Iranians make any move to threaten the Strait of Hormuz, there would be tremendous pressure on the U.S. government to respond with overwhelming force to reopen the Strait, deny Iran the capacity to further threaten the United States or our allies, and convince Tehran to stop attacking us.
Depending on the extent and length of this retaliatory damage, there is a real risk of an escalatory spiral between the two sides that would lead to a much wider war. War games of small-scale crises between Iran and the United States have repeatedly demonstrated how easy escalation is between the two countries, given the hard feelings, deep suspicions, constant misinterpretations, and painful history between them. Similar studies and simulations of a conflict with Iran have also pointed to the difficulty of bringing such a war to an end short of an invasion—something reinforced by America’s difficulties convincing Iran to desist during the “Tanker War” of the 1980s.95
Second, any American president who commits the United States to war with Iran, even if it starts out with discrete air strikes, will have a difficult time halting operations short of Iran’s full capitulation (at least on the nuclear issue), regardless of the success or failure of that air campaign. If the president goes before the nation and explains that the threat of a nuclear Iran to American interests is so grave as to warrant the United States going to war with Iran (unprovoked) by launching hundreds or thousands of air sorties against dozens of Iranian targets, possibly resulting in hundreds or even thousands of deaths, he or she is not going to be in a position to announce a few weeks later that the strikes failed and Americans will just have to learn to live with a nuclear Iran. Nor is the president going to be able to accept a defiant Iran announcing after successful air strikes that it will rebuild its nuclear program and this time will not stop with enrichment but will continue on to field an arsenal. In either circumstance, if the threat were that grave to begin with—grave enough to court retaliation that could result in further American casualties—the American people would demand that we commit more of our fearsome military power to finish the job.
It is conceivable that the air strikes will do the job on their own and will either bring about a regime change or convince the Iranians not to begin rebuilding their nuclear program. It is also possible that Iran will retaliate in a modest fashion so as not to provoke a larger American response, or that Iranian retaliation will be defeated by American countermeasures and whatever pain we suffer will be modest enough to ignore or to respond to with equally limited measures.
However, these more optimistic scenarios appear to be the less likely outcomes. Although the United States is in a far stronger position than Israel would be on either of these scores, it appears more likely that the Iranian regime will not be overthrown and that whatever damage the air strikes may do, it seems probable that the regime will choose to reconstitute rather than give up. Likewise, the Iranians will almost certainly try hard to inflict considerable damage on the United States and will have a good chance of doing so.
No American president could order air strikes without recognizing the likelihood that doing so will end up committing the United States to a wider war with Iran and possibly a ground invasion. More to the point, it would be irresponsible for a president to order air strikes against Iran without having accepted that doing so may mean committing the United States to an eventual invasion.
As we should have learned from our painful experiences in Afghanistan, Iraq, and the Balkans, when the United States starts down the path of military action it is extremely difficult for our nation not to walk that road to its very end, whatever that end may be. In all of those cases, the United States tried limited military operations at first, only to find itself forced to commit to larger operations and eventually a major invasion and occupation. In the case of the Balkans, Milosevic’s concessions on Kosovo in 1999 ultimately obviated the need for ground invasions and limited the extent of the postwar commitment. However, the United States was reluctantly gearing up for a ground invasion just when Milosevic’s capitulations relieved us of the need to actually execute it. The same might happen in Iran, but no responsible president could start down the path of military action assuming it will. And unfortunately, the pathologies of the Iranian regime create the very real likelihood that it will require a much greater military effort, even an invasion and occupation of the country, either to prevent it from reconstituting its nuclear program or to force it to halt its retaliatory attacks against the United States.
It is easy for those who do not sit in the Oval Office to dismiss the prospects of a wider war with Iran or the need for an invasion and occupation of the country growing from “limited” air strikes against Iran’s nuclear program. The person who sits there cannot. He must think through what his decision will entail, what it may commit the United States to accomplish. It would be reckless and irresponsible for him to assume that air strikes would not lead us into a situation requiring a greater military effort.
Since air strikes against Iran raise the specter of an invasion, unwanted though this would be for virtually every American, it is important to sketch out the basics of such an operation.
MILITARY ASPECTS OF AN INVASION.96 As with Iraq and Afghanistan, the military requirements for an invasion of Iran could prove deceptive. The invasion itself would be a major military operation, but one well within the capability of American forces. Although Iran’s armed forces are roughly twice as large as Saddam’s were in 2003 (750,000 to 1 million in the Iranian Armed Forces today, compared to about 400,000–500,000 in Iraq’s various military services then) and probably would perform somewhat better than the Iraqis, they are outclassed by the American military. Once in, however, a long-term commitment would be necessary, greatly increasing the likely requirements.
A U.S. invasion force would face two primary military obstacles against Iran: terrain and insurgents. The first of Napoleon’s “Military Maxims” was “The frontiers of states are either large rivers, or chains of mountains, or deserts. Of all these obstacles to the march of an army, the most difficult to overcome is the desert; mountains come next, and broad rivers occupy the third place.” Iran has few broad rivers, but many mountains and deserts, the hardest types of military terrain. Iran has considerable experience with guerrilla warfare through its long association with Hizballah and the support it provided for the latter’s guerrilla wars against Israel in southern Lebanon. After watching the American blitzkrieg to Baghdad in 2003, the Iranians have concluded that the best way to fight the U.S. military would be through a protracted guerrilla war, bleeding American forces as they wend their way through the arduous mountain chains that fence in the Iranian heartland and wearing them down in what Tehran has dubbed a “mosaic defense.”97
To deal with the terrain and Iran’s defensive strategy, an American invasion of Iran would require a variety of forces. First, it would probably involve a significant contingent of Marines (two to four regimental combat teams, or about 15,000–30,000 Marines) to seize a beachhead and then a major port at one of four or five general locations where such a landing could be staged along the Iranian coastline. To get past the mountains, the United States would want large numbers of air mobile forces—the brigades of the 101st Air Assault Division and the 82nd Airborne Division, and possibly the 173rd Airborne Brigade as well. Beyond that, the United States would want at least one, and as many as three, heavy armored divisions for the drive on Tehran itself (depending on the extent to which the Marines and air mobile units are tied down holding the landing area and mountain passes open, as well as providing route security for the massive logistical effort that will be needed to supply the American expedition). A force of four to six divisions amounting to 200,000–250,000 troops may lead the charge, larger than that employed at any time during Operation Iraqi Freedom and much larger than the 55,000 ground troops that took down Saddam’s regime in the initial invasion.
Although Washington might secure bases in the Gulf states (and perhaps in some Central Asian countries as well), it seems unlikely that Iraq, Turkey, Pakistan, or Afghanistan would allow us to mount the invasion from their territory. Consequently, an invasion would require a large naval contingent to secure the Persian Gulf and carry the invasion force to the shores of Iran. It is thus unlikely that the United States could launch such an enormous military operation without the Iranian government getting a sense of what was headed its way.
In these circumstances, where the regime’s survival would be at stake, the Iranians would have no incentive to show restraint in fighting back any way they could: with terrorist attacks anywhere they could hurt Americans, with rocket and missile attacks across the Persian Gulf, and by trying to close the Strait of Hormuz. Iran has some dangerous air, sea, and missile capabilities, but, as noted earlier, if the U.S. Navy and Air Force brought their full might to bear, they could crush Iran’s air and sea defenses in a matter of weeks or months. This effort, however, would require a major commitment of American minesweeping, surface warfare, and air assets. It also would require a cutoff of Persian Gulf oil flows for at least as long as the Iranians contested the waters of the Gulf and the Strait.
As with an air campaign against Iran, the U.S. Air Force and Navy probably could handle the airpower requirements without the use of Saudi, Kuwaiti, Qatari, Emirati, Omani, Turkish, or Central Asian air bases, but it would be much easier with them. Long-range bombers could fly from the continental United States or Diego Garcia (with British permission), but unless the Gulf or Central Asian countries could be persuaded to allow the U.S. Air Force to operate from nearby airfields, the vast majority of American aircraft would have to operate from aircraft carriers. Given the extent to which modern U.S. ground operations rely on air support, three or more carriers might be needed for this campaign, at least until Iranian air bases could be secured and developed to handle U.S. Air Force planes.
Similarly, if the United States were denied access to its many bases in the Persian Gulf region, the Navy would have to bring in everything needed to support the invasion, and U.S. engineers would have to build facilities at Iranian ports to enable them to support a massive force. Indeed, because the expanses of Iran would be much greater than in Iraq (distances from major Iranian ports to Tehran are anywhere from one and a half to three times as great as those from the Kuwaiti border to Baghdad), and because of the much more difficult terrain, the logistical requirements for an invasion of Iran could be considerably more demanding than those for Iraq.
THE OCCUPATION. So much for the takedown. Now to the hard part. In both Iraq and Afghanistan, the United States tried to get rid of the regime and then go home, leaving the country in the hands of a hastily cobbled-together successor government of exiles. In both cases, the effort failed, and the country began to descend into chaos. In both places the Bush 43 administration was forced, against its will, to embark on a long-term occupation and reconstruction of the country.
It is unimaginable that the United States would not find the exact same thing in Iran. Iran is an even bigger oil producer than Iraq. It too occupies a central position in this vital region. Its influence and relationships throughout southwest Asia make it a key actor. If it fell into civil war and chaos, the spillover would infect the entire region. And the occupation of Iran would be a major undertaking.
This will likely prove true even if Washington has learned all the lessons of Iraq and mounts the invasion and occupation of Iran exactly as it should have in Iraq. Iran is a much bigger country than Iraq, with nearly three times the population and roughly four times the landmass. It too has myriad ethno-sectarian divisions and grievances, and a traumatic history of sanctions and authoritarian misrule. Thus the challenges of occupying and building a stable new Iran are likely to be nearly identical to those of Iraq, just bigger.
All low-intensity conflict operations, whether a counterinsurgency campaign or a stability operation like securing post-invasion Iran, require large numbers of security forces, because the sine qua non of success is securing the civilian populace against widespread violence. Scholars and low-intensity conflict experts have found that it takes about 20 security personnel per 1,000 people to secure civilians against insurgencies, militias, and other forms of violence common in postconflict reconstruction.98 This ratio suggests that an occupation force of 1.4 million troops would be needed for Iran. That ratio is basically the same that succeeded in stabilizing Iraq in the 2007–2008 “surge” (taking into account American troops, security contractors, allied contingents, and the enlarged and improved Iraqi Security Forces).99
There is reason to believe that high-quality troops with lavish support assets (like the U.S. military) can get away with less than the canonical figure. But even if the United States, by relying on far superior training, technology, and tactics, could cut that number in half, the remainder still represents the entire active-duty component of the U.S. Army and Marine Corps. Even if it were only necessary to maintain such a large force for the first six months, after which the United States could begin drawing down its forces quickly (as experience in the Balkans and even Iraq suggests is possible), such a commitment would still require a massive mobilization of the National Guard and both the Army and Marine Reserves.
Again, assuming a best-case scenario in which the proper application of the lessons learned from Iraq and Afghanistan enables the invasion and occupation of Iran to go more easily, it would still take years to establish a stable, legitimate government with competent, loyal security forces. During that time, the United States would doubtless have to maintain several hundred thousand troops in Iran, even under ideal circumstances of full Iranian cooperation and minimal resistance.
THE COSTS OF AN INVASION. Of course, it would be unwise to assume the best case. The Bush 43 administration’s insistence that only the best case was possible in Iraq lies at the root of the concatenation of mistakes that produced the worst case there from 2003 to 2006. Iranians are nationalistic, and while many would welcome the end of the current regime and a better relationship with the United States, the evidence suggests that most would oppose a U.S. invasion. Indeed, the fact that the regime is preparing to wage a guerrilla war against the United States if it invades means we could have a long, hard slog ahead of us there.100
The United States lost nearly 4,500 troops securing Iraq, and more than 2,000 in Afghanistan as of early 2013, although it did not have any killed during the earlier occupation of Bosnia. It is impossible to know how many troops we might lose in a similar operation in Iran, but we should not assume it will be as easy as Bosnia, and it could be as costly as Afghanistan or Iraq, or worse. Hundreds or possibly thousands of American military personnel would die in the invasion itself. Thereafter, casualty levels would depend on both the extent of Iranian resistance and the competence of the American security effort. The remarkable success of American forces in Iraq after 2007 demonstrated that the right numbers of troops employing the right tactics in pursuit of the right strategy can secure a country at much lower cost in blood than inadequate numbers of troops improperly employed. Prior to the surge—and during its heated early months when U.S. troops were fighting to regain control of Iraq’s streets—American military deaths were running at seventy to eighty per month. Once that fight had been won, they fell to five to fifteen per month. U.S. casualties during the occupation and reconstruction of Iran could thus vary considerably. Only in the best-case scenario—where the securing of Iran is as smooth as NATO’s securing of Bosnia—should policymakers expect minimal casualties. In more plausible but still favorable scenarios, where Iranian resistance approximates Iraqi levels of violence after the surge, the United States should still expect a dozen soldiers and Marines killed each month, on average, for several years. In worst-case scenarios, in which the United States mishandles operations in Iran as badly as it did initially in Iraq, those numbers could run into the hundreds each month, or worse.
Washington would have to expect Tehran to retaliate against American targets outside of Iran, too. In the case of an invasion, the Iranians would have no reason to show restraint and every reason to try to hurt us as much as they possibly could to try to get us to back off. Iran has a more formidable ballistic missile arsenal than Saddam had in 1991 and a far more extensive and capable network to mount terrorist and cyber attacks against the United States and our allies. Whether the Iranians could pull off a catastrophic attack—along the lines of 9/11—would depend on how much time they had to prepare for such an operation, how well developed their contingency plans were at the time, and how well American defenses performed. Iran has one of the most competent terrorist networks in the world, we worry that they have much more powerful cyber-weapons in reserve, and they may actually have some of the WMDs that Saddam did not. Even if such attacks ended with the fall of the regime, since an invasion might take six months or more from the time the first U.S. Navy warships began to clear the Strait of Hormuz to the removal of the clerical regime, the United States would have to prepare to prevent such attacks—and live with the failure to do so—for at least this stretch.
The monetary costs of an invasion of Iran would be incurred principally in the initial invasion, the number of troops needed for occupation multiplied by the length of time they would be needed, added to the financial cost of casualties, and whatever money was directed at Iran for economic assistance and reconstruction. By way of comparison, the Iraq War cost $806 billion over roughly eight and a half years.101 That strikes me as a good minimum of what we ought to be prepared to pay in Iran given its greater size, even taking into account the lessons we have learned from Iraq and Afghanistan. Most of these costs would be spread out over five to ten years, which would diminish their impact, but they would not be negligible.
In addition to the costs, an invasion also entails running a significant set of risks. A botched reconstruction, like the one in Iraq, could unleash a Pandora’s box of problems both inside the country and out. Various Iranian ethnic groups might declare independence, setting off a civil war with the country’s Persian majority and creating the risk of drawing in Iran’s various neighbors. Iran’s oil wealth would be a major driver of both internal conflict and external intervention. Chaos and conflict could jeopardize Iran’s oil and gas exports, and would complicate the security problems of Iraq, Afghanistan, and Pakistan.
There is one important exception to all of these points about the costs of and risks of the military options. If, for whatever reason, Iran attacks the United States first, the logic behind many of the downsides to air strikes against Iran may be mitigated or even reversed. In these circumstances, bombing Iran would not only become a much more desirable (or at least, much less undesirable) approach; it might even be a “good” option.
There are many possible scenarios for why and how Iran might strike first. In one crisis simulation we ran at Brookings in 2012, we posited that a combination of U.S. cyberattacks and Israeli covert action prompted Tehran to mount terrorist attacks against both an American and an Israeli, and the hit on the American ended up inadvertently killing a large number of American tourists in the Caribbean. Modeled roughly on the Arbabsiar plot, the attack prompted the U.S. team to respond in what it saw as a measured, discreet way—a cruise missile attack against a remote IRGC base where the Revolutionary Guards trained and equipped Taliban fighters to kill Americans in Afghanistan. The American team felt that this was the absolute minimum that they could do in response to such a brazen Iranian terrorist attack. But the Iran team went ballistic—almost literally—and responded far more aggressively than the Americans had expected. Iran made moves in the Strait of Hormuz that convinced the Americans (and much of the rest of the world) that Iran was trying to close the Strait. As the game ended, the debate within the American team was over whether to obliterate all of Iran’s naval, air, and missile forces around the Strait of Hormuz, or to obliterate all of those forces and take out Iran’s nuclear sites as well.102
It isn’t hard to imagine other circumstances in which American actions, or Iranian perceptions of American actions, could lead Tehran to take actions of their own that the United States and the rest of the world would see as outrageous, unprovoked acts of war. In the 1980s, Iran’s misunderstanding of American actions and our role in the Iran-Iraq War led Tehran to attack American forces in both Lebanon and the Gulf. Likewise, in the 1990s, Iranian misperceptions of an aggressive U.S. covert action program against them led them to hit the Khobar Towers complex. The Arbabsiar plot is another example, although it might have been in response to real American actions, not just imagined.
In the event that Iran overplayed its hand, many of the problems attendant on air strikes against its nuclear program might abate or even turn around. First, the American people would be enraged and would demand that the United States strike back, and strike back so hard that Iran would never think about conducting another one. Iran’s nuclear sites would be the ideal target for such a response: they are part of an Iranian enterprise that the UN Security Council has demanded Iran halt. They are a threat to the stability of the region, a point echoed by all of the great powers, including all five permanent members of the Security Council. They are a threat to American interests in the region, and those of our regional allies. And they are valuable to the Iranian regime.
So the president could count on strong domestic backing and little international opposition—and possibly strong international support, just as the United States enjoyed tremendous international support after the 9/11 attacks. Many people around the world would see Iran as a dangerous, rogue regime supporting terrorism, and many more would feel that the Iranians had only themselves to blame. Because Iran would be seen as the aggressor, it would be much easier to maintain the sanctions and inspections in place after a strike. It would be much harder for the Iranians to play the victim as cover to withdraw from the NPT. Iran would look even more like a dangerous country that needed to be restrained, contained, and prevented from acquiring a nuclear capability.
Perhaps of greatest importance, it would also be much easier for the American president to refrain from further escalation and so avoid being pulled into an invasion. If Iran attacked us, that would be the justification for the attack. The president would not have to convince the American people of the dangers of the Iranian nuclear program. Iran might retaliate, but the United States could also continue to respond against other target sets—Iranian conventional forces around the Strait of Hormuz, Iranian oil facilities, Revolutionary Guards facilities, air force bases—without feeling the need to finish off the regime once and for all. Of course that risk would not be entirely absent. If Iranian retaliation also proved far more painful than expected—if Iranian cyber or terrorist attacks killed large numbers of people in the United States, for instance—then the president might still feel such pressures.
A clear and outrageous Iranian provocation will create the most advantageous circumstances possible for the United States to use force to take out Iran’s nuclear program. It might even make this the preferable course of action. But like everything with Iran, it is not without costs and risks. With Iran, the worst is always a possibility.