9

The Role of Nuclear Weapons in the Twenty-first Century

Most discussions of nuclear weapons start from one of two polar opposite assumptions—either they are a liability and should be eliminated, or they are essential and must be maintained. Some view nuclear weapons as inherently immoral, unnecessarily destructive of civilian populations, and unusable in any “just war.” Others see them as bulwarks against evil, an assurance that the world wars that decimated the twentieth century will not blight the twenty-first. Coming from opposite directions, and lacking much in the way of factual information with which to frame a debate, it is little wonder that American nuclear policy has seen scant change since the end of the Cold War. But nuclear weapons are too important to let our policy drift, carried by the momentum of a different era. If we elect to continue to have them, we must understand why, how many we need, and the purpose we intend for them. If we elect to eliminate them, we should understand the challenges and the risks that will follow.

I strongly believe that a meaningful discussion of the future of nuclear weapons must start by considering the geopolitical context in which they exist and the military requirements they are intended to meet. Is deterrence still a valid concept since the end of the superpower standoff, or should we create a new doctrine, perhaps one based on the precision use of low-yield nuclear weapons for tactical applications? Is there any place at all for countervalue strategies that target cities as a means of striking fear in the hearts of potential aggressors, or should we continue a counterforce strategy that targets only military capabilities posing an imminent threat to the United States? On a more fundamental level, do we need nuclear weapons at all at a time when our country has a substantial conventional military advantage?

 

NUCLEAR WEAPONS PLAYED a key role in the Cold War standoff between the capitalist West and the communist East. Each side saw them as the ultimate insurance that it could not be defeated, at least militarily, and each saw them as cost-effective force multipliers on the battlefield—one nuclear weapon could substitute for thousands of troops. Nuclear weapons served both strategic and tactical roles, the former played out upon the broad stage of international relations and the latter working at the level of the tank, ship, or bomber. Today we face a fundamentally different set of world conditions that play no less significant a role in shaping our thinking about nuclear weapons than did the superpower standoff.

The Soviet Union, the principal driver for the development of American strategic weapons, is gone, but the Russian Federation is modernizing its massive and capable nuclear arsenal. Russia is the only country in the world with a sufficient nuclear force to utterly destroy America—the mere existence of these weapons demands that we factor Russia into our nuclear strategy.

Some commentators discount the future of Russia, citing the huge problems the country faces in reforming a dilapidated industrial plant and in dealing with a shrinking population beset by poor health, emigration of its best and brightest to other countries, and government corruption. While their reasoning is compelling, it is also true that this unique country has been in worse shape and recovered rapidly. Russia was in ruins at the end of the First World War and the Revolution. Millions had died and the national infrastructure had nearly collapsed. However, within a generation Russia was back on its feet and boasted one of the world’s largest air fleets, a massive army, and an impressive university system. More than twenty million Soviets perished in the Second World War, many at the hands of the Stalin regime. European Russia, home of much of the country’s industry, was again in ruins. But the Soviet Union detonated an atomic bomb just four years after the end of the war, and it launched the world’s first artificial satellite in 1957—about a half generation after the war ended. Russia suffered a series of catastrophes in the twentieth century, but it recovered from each of them in less than a generation. We are now nearly a full generation past the breakup of the Soviet Union.

Current trends in Russia, which are remarkably predictable, suggest that the country will reemerge as a significant military power. Russia has periodically flirted with Western-style reform, only to experience problems that drove it back to a strong central government. President Vladimir Putin, the most capable and energetic Russian leader in many decades, reversed a liberal trend toward decentralization and consolidated power in the Kremlin. No longer does one hear talk of the oblasts (local states) becoming “semi-autonomous regions.” Governors are appointed by, and directed from, Moscow. The government has taken control of most of the press, has placed stringent new laws on the operation of foreign organizations on Russian soil, and has reasserted its historical ascendancy over the armed forces.

Russia recognizes the inferiority of its conventional military forces and, just as NATO did during the Cold War, is using its nuclear weapons to compensate. It announced a new generation of low-yield weapons for use on accurate short-range ballistic missiles placed around the country’s borders, a clear signal to anyone who would covet resource-rich areas in the South and East. On the strategic front, Russia is modernizing its ballistic missile fleet with the SS–27 ICBM. There are hints that the single warhead on the SS–27 is capable of maneuvering to avoid ballistic missile defenses, another signal that Moscow is not to be trifled with in the nuclear arena.

Russia is no longer considered a strategic adversary of the United States, but it must still figure prominently in any discussion of our nuclear arsenal. One of the chief functions of nuclear weapons is to counter any potential threat on the strategic scale, no matter how unlikely it may now appear. Another is to prevent threats from arising by making the risk too great for the potential aggressor. Factoring Russia into our future nuclear requirements is not an argument for restarting the arms race, a wasteful and unnecessary act on either side’s part. It simply recognizes that Russia continues to maintain and modernize one of the largest strategic nuclear stockpiles in the world. Until and unless Russia reverses the expansion of its nuclear arsenal, it would be foolish to ignore it.

 

CHINA IS OFTEN mentioned as a future peer competitor of the United States. Some generals are convinced that war between America and China is inevitable—a chilling echo of General Curtis LeMay’s recommendation for a massive preemptive strike on the Soviet Union. China’s astonishing economic growth and its continuing threat to take Taiwan by force are two principal concerns. Construction in major Chinese cities is so rapid that it is placing strains on the world’s ability to supply construction materials. China consumes 40 percent of the world’s concrete, and its appetite for dwindling reserves of oil is growing faster than that of any other country. The list of Chinese millionaires seems to grow daily. Some experts predict that China’s economy could outstrip that of the United States within twenty years.

China, with its population of more than one billion people, can exert influence not only as a provider and consumer of goods and services, but also as a military power. Few other countries could hope to field an army as large as China, and few countries could absorb more punishment in a major war and continue to function.

Linear projections of growth often ignore serious underlying problems, of which China faces many. China is in the midst of a demographic crisis, ironically one arising from the success of its birth control programs. Concerned about its ability to feed a massive and growing population, China limited households to one child, with sanctions against couples who had more. This policy, combined with the traditional Chinese preference for male offspring, resulted in a fundamental imbalance in age and sex distribution, with prospects for a large class of older people reliant on a small number of young men for support. The country lacks an effective social security system, so a young Chinese man may find himself responsible for supporting six other people, including his wife, child, parents, and in-laws—not to mention any other relations who do not have male children to help them. Such a burden restricts the ability of a young family to save and to buy durable goods supplied by domestic industry.

Perhaps even more challenging is that the majority of Chinese live in the countryside, with poor medical care and education. These rural peasants are demanding services comparable to what they see in cities such as Beijing and Shanghai, and the central government, still at least nominally communist, clearly understands that these demands cannot continue to go unmet without serious trouble.

China boasts massive armed forces, but closer inspection reveals that the quality of its equipment is well behind that of the United States, Russia, and other developed countries. The Gulf wars demonstrated that numbers alone are no match for technologically superior forces. The People’s Liberation Army and Navy learned this lesson and embarked on a program of modernizing everything from soldiers’ rifles to submarines.

With only a few dozen missiles capable of reaching the United States, each of which is said to be equipped with a multimegaton warhead, China appears to be squarely in the countervalue targeting camp; that is, its weapons are pointed at cities rather than military targets. One might assume that China considers its nuclear arsenal an insurance policy against major strategic aggression, not an instrument of preemptive war. Objections to America’s deployment of national missile defense led China to threaten to increase its number of deployed missiles and to equip them with a more accurate and improved warhead, but the speed with which they will pursue this modernization remains to be seen.

I think that China will remain focused on internal and economic issues for some time to come, perhaps for a generation or more. Beijing is developing diplomatic and trade relationships around the world, including in developing Africa and other resource-rich areas. It appears to have little appetite for aggression that could put it at odds with America, a huge consumer of Chinese manufactured goods. Periodic bursts of rhetoric over Taiwan are to be expected, given strong historical feelings about unification, but one must question whether Beijing wants the island enough to risk a major war that would return it to a position of isolation after years of trying to integrate itself into the global community.

 

THE PROLIFERATION OF nuclear, chemical, and biological weapons has increased over the past two decades, with India, Pakistan, and North Korea testing nuclear weapons and Iran apparently pursuing them. In each of these cases, one could argue that the country involved saw nuclear development more as a means of assuring national sovereignty than as a threat to the United States or other Western powers. Their arsenals are small and their means for delivering weapons are limited, although the rapid proliferation of ballistic missile technology may soon give even small countries the ability to deliver nuclear weapons over intercontinental distances. No developing country is likely to represent a strategic challenge to the United States anytime soon, and all of them recognize that the conventional military forces of the United States are capable of inflicting major damage even without resort to nuclear weapons.

Nuclear weapons are no longer needed to deter a massive Soviet attack on the United States or an invasion of Western Europe. However, just as they did during the Cold War, they maintain a strategic balance, assuring each side that it cannot hope to prevail over the other. This balance has spread beyond the dyad of the United States and Russia—other nations recognize America’s conventional military supremacy and have decided to weather international condemnation to build the only type of weapon that could defeat us on the battlefield.

 

IN CHAPTER 5, we discussed new technologies that can perform missions previously assigned to nuclear weapons—without incurring the huge political cost associated with crossing the nuclear threshold. The United States Strategic Command has been integrating some of these ideas into its strategic war plans, reducing the need for nuclear weapons while achieving comparable levels of confidence in the outcome of any engagement.

However, there are still some cases where nothing short of a nuclear weapon will do the job. WMD facilities located deep underground, or in tunnels bored into mountains, cannot be defeated by conventional weapons no matter how precisely they are guided to the target. Only the explosive force of a nuclear weapon will destroy them, and only by keeping a sufficiently capable nuclear arsenal can we warn potential adversaries that even their best efforts at hardening will ultimately fail.

There is another aspect of nuclear weapons policy that gets much less attention today: the threat of attacking cities, industrial centers, and cultural assets, the countervalue strategy that we have repeatedly tried to distance ourselves from due to its enormous cost in human life. I hope that the United States will continue to avoid purposeful targeting of civilian populations, but it is naïve to ignore countervalue targeting as a component of deterrence. Enemies will always know that the United States has the capability to destroy their cities, and they will factor this into their decision calculus. Other countries, particularly those with only a few nuclear weapons, are likely to continue to employ countervalue strategies as the core of their nuclear deterrent posture for the simple reason that they lack the numbers and types of weapons to implement a counterforce approach. The subtleties of policy aside, nuclear weapons are blunt instruments of warfare, icons of mass destruction.

 

NUCLEAR STRATEGY IS complex because it must deal with uncertain futures—both the geopolitical context in which such weapons will exist and a constantly evolving set of military technologies both here and abroad. Before beginning a discussion of alternate nuclear futures, I would like to propose six basic considerations that could frame a debate on the role of nuclear weapons in the twenty-first century.

  The fundamental role of nuclear weapons is to maintain strategic peace. I know of no military commander who anticipates the need to use nuclear weapons in any case short of the survival of the nation. We no longer need nuclear weapons to compensate for quantitative or qualitative weaknesses in our conventional forces. We should emphasize that these are strategic weapons, the ultimate guarantors of the survival of our country against state-level aggression. We should work toward the elimination of tactical nuclear weapons and insist that other countries do likewise, raising the threshold for any possible use of these uniquely destructive weapons.

  The United States should be among the last nations to use nuclear weapons. Our use of a nuclear weapon could justify another country in using one against us. Only when we, or an ally, have already been struck by a weapon of mass destruction, or when we are absolutely convinced that such a strike is imminent, should we consider the use of nuclear weapons. The United States should constantly emphasize that nuclear weapons are qualitatively different from other types of weapons and that any nuclear use crosses a fundamental threshold in international relations. Our conventional military superiority means that we can win any battle without resorting to nuclear weapons.

  The United States should adopt a policy of purposeful ambiguity regarding the first use of nuclear weapons. To state outright that we will not be the first to use nuclear weapons sends a clear signal to a potential adversary that it can be the first to throw a nuclear punch. There is value in ambiguity in that it complicates the attack plans of a future adversary. We must be careful, however, that we are not so ambiguous that we tempt an adversary into launching a first strike against us in fear that we are about to attack.

  The assurance of massive destruction is an implicit element of deterrence. The United States should continue to employ a counterforce strategy, one that focuses on reducing or eliminating the enemy’s ability to inflict damage on our country. But we should remember that other countries will worry about the loss of cities and vital resources. Purposeful ambiguity will raise questions in the minds of potential adversaries, questions that will constrain their actions and, hopefully, prevent them from attacking us. The threat of massive nuclear retaliation—whether explicitly stated or not—is part of any perception of nuclear weapons.

  Nuclear weapons are primarily instruments of state-to-state deterrence. Critics of nuclear weapons argue that they have little value in deterring terrorists. I agree with this assessment. Nuclear weapons serve as deterrents to state-level entities that have assets that can be held at risk. They are ineffective when the enemy is not concentrated in a given area or when they lack military assets that, if destroyed, would lessen the threat to the United States.

  We should assume that we will never have enough intelligence to confidently assess the capabilities and intents of other nations. The record of the intelligence community for predicting or even detecting events is poor. Numerous studies have examined why, but in reality we will never be able to know everything in a world dominated by human behavior. We must learn to live with uncertainty, particularly on the strategic front, and configure our nuclear arsenal so that it can respond to the broadest range of future contingencies.

Are there any conditions in which the United States might use nuclear weapons? Are they really no more than an existential deterrent, threatened but never used? There are several situations where the limited use of nuclear weapons could prevent catastrophic damage to the United States. Suppose that North Korea, in an insane demonstration of its military power, were to launch a nuclear weapon against Los Angeles, with bellicose threats that San Francisco is next. Having suffered one attack, with a credible threat of a second, the United States might respond in kind by a limited nuclear attack against North Korean missile locations and military installations.

Suppose that, in a future war, we had unambiguous intelligence that an enemy was about to launch a new type of biological attack against our troops, one for which we had no defense and that could cause hundreds of thousands of casualties. If we knew the location of the enemy missiles, we could incapacitate them via conventional means. But suppose that the enemy’s biological weapons storage site was buried so deep that only a nuclear weapon would destroy it?

There are no optimal solutions to either of these problems. Not using nuclear weapons might lead to horrific losses on our side. Using them could lead to more nuclear weapons being launched in the future, perhaps against us. The decision the president makes will depend on the details of the situation. Nuclear weapons provide him or her with an option, an ultimate weapon for use against an ultimate threat.

 

HAVING BRIEFLY ESTABLISHED the context for nuclear weapons in the coming decades, we can now address the questions posed at the beginning of this chapter, namely how many we need and what types. I divide the discussion into four options: the abolitionist position, the minimalist position, the maximalist position, and the moderate position. Each will be discussed in turn, but special attention will be given the moderate position as I believe that it is the best choice for the United States.

The Abolitionist Position

Every president of the United States since the invention of nuclear weapons has discussed their elimination. The problem is that no proposal has been put forward to enable us to verify that the nuclear forces of every country in the world have been reduced to zero. Nuclear explosives are so powerful that only a few could create a decisive strategic advantage, something painfully demonstrated at Hiroshima and Nagasaki. One need only imagine a situation in which America had disarmed, only to be threatened by a country that openly tested a nuclear explosive and claimed that it had more at the ready.

Our inability to be sure that, once we disarm, others have done likewise is the standard argument against the abolition of nuclear weapons. However, advances in nuclear detector technology and the success of international agreements for mutual inspections suggest that we take another look at barriers to the elimination of nuclear forces. Is verification of disarmament really impossible? Is there a technology that, combined with a set of inspections, could provide adequate confidence that no country or group had a nuclear weapon or the means to produce it?

This is not as far-fetched as it might sound. The Open Skies Treaty of 2002 is an agreement among thirty countries, including the United States and Russia, that allows photo-reconnaissance flights across their territory. American crews fly missions along predefined routes in Russia, and Russian crews do the same in the United States. We could extend this treaty to equip low-flying aircraft with radiation detectors that could identify large quantities of nuclear material. A determined cheater could move materials inside a mountain or deep underground, foiling detection, but we might think of other methods to deal with this possibility.

The second argument frequently used against abolition—that an adversary with only a few nuclear weapons could intimidate the United States or other countries—also begs closer scrutiny. A few weapons, even of the multimegaton class, would wreak incredible destruction on a few American cities, but they would not destroy the fabric of our country and they would not eliminate our considerable conventional military capability. The United States, along with other outraged nations of the world, would still be able to wage war and defeat the nuclear aggressor using conventional forces. Nuclear weapons would play a potent role in international blackmail, but they would not carry the day. Moreover, the advent of an effective missile defense system, combined with nuclear detectors at our borders and seaports, would make it more difficult for a potential attacker to deliver one or a few weapons.

An alternative to the total abolition of nuclear weapons is to place a small number of them under international control, something proposed by the Truman administration when America was the sole nuclear power. This approach avoids the dilemma of proving a negative—that no country has or is developing nuclear weapons—but it suffers from the need to empower an international body with using nuclear weapons. What are the criteria for nuclear use? What countries get to decide? Would there be a veto authority? America has traditionally been suspicious of granting power to international bodies, at times fearing entanglement in foreign wars and at other times rejecting the need to submit to any authority beyond its own. And even if America agreed, would North Korea and Iran? Would France? International control of nuclear weapons is not impossible, but it faces huge hurdles that will take some time to resolve.

Nuclear abolition is sometimes promoted based on philosophical or religious grounds that view nuclear weapons as inherently immoral. Such arguments are unconvincing to others who see these weapons as a practical response to a manifestly dangerous world. We must move beyond such unproductive debates. Rather than reject abolition out of hand or naïvely pursue it, we need to conduct a rigorous study of its challenges and potential solutions to those challenges, placing all the facts on the table for a rational discussion.

The Minimalist Position

If it is not realistic to eliminate all nuclear weapons, could we at least reduce their numbers so that they no longer represent the threat to human civilization that they did during the Cold War? General Andrew Goodpaster, adviser to President Eisenhower, recommended that we might go as low as one hundred weapons, enough to cause great damage in a counterattack, but not enough to ensure victory in a preemptive strike against another nation. This would put America in a comparable position to Great Britain, France, and China and might encourage Russia to follow a similar path.

Another formulation of the minimalist position suggests separating warheads from missiles to lessen the probability that they would be used in a moment of uncertainty or even anger. We would still retain the weapons, but everyone would be able to see that they were not ready for immediate use, greatly reducing the so-called hair-trigger danger of launch. In this scenario, nuclear-armed submarines would remain in port except in a crisis situation, in which case warheads would be installed and the ships would sail.

The hair-trigger argument for separating warheads and missiles is fundamentally flawed. Nuclear weapons can only be launched and detonated following an order from the president of the United States. Local commanders of missile bases, submarines, or bombers do not have the ability to independently order an attack. Launch authority comes from the president in the form of a multidigit code that is unbreakable by any known or projected means. Codes are contained in sealed containers always at the president’s side and are constructed in such a way that no human eyes see them during their production. The launch of a nuclear attack is highly choreographed for the precise purpose of avoiding hasty launch.

The minimalist option ignores several practical considerations. First, there is the problem of how to define “one hundred weapons.” Is it the total number of weapons in the stockpile, or only those that are capable of being quickly mated to missiles and aircraft? What about weapons included in the supply chain, those undergoing refurbishment or remanufacture? What would happen if a fatal flaw was discovered in the stockpile, one that rendered it unsafe or ineffective? Should a reserve force of a different design be maintained, one that could be quickly substituted for the ailing weapons?

Second, how should we deploy a small number of weapons? Only on survivable submarine-launched ballistic missiles, as the British do? Should we continue to maintain a triad of land-based ICBMs, submarine-launched SLBMs, and bombers? If more than one delivery option is deemed necessary, how should we best divide the small stockpile among them?

Third, the minimalist position has the same problem of verification faced by the abolitionist position, namely the difficulty of locating and placing under suitable controls all nuclear material that a potential adversary could use to construct additional weapons.

Lastly, and perhaps most importantly, a small nuclear stockpile could actually increase the probability of nuclear war, tempting an attacker to think that it could destroy all or most of our weapons in a first strike, effectively eliminating our ability to respond. The attacker could then dictate terms while threatening a second strike. Removing warheads from missiles has a similar destabilizing effect, since if, during a crisis, we were to remate them or order our submarines to sail, tensions could escalate to the point of war.

The minimalist position offers the apparent attraction of limiting the (still horrific) destruction that would result from a nuclear war, but it suffers when one looks more closely into the details. It is not clear whether the arbitrary reduction of our weapons to a few hundred would reduce or increase the probability of war.

The Maximalist Position

The maximalist position, still held by some in the nuclear policy community, argues that the United States should maintain a sizable arsenal to respond to any contingency, including the emergence of a nuclear peer competitor. This is especially important, they maintain, during a period when the United States does not have the ability to manufacture new nuclear weapons in any quantity.

Conservative calculations suggest that to maintain an arsenal of two thousand deployed strategic weapons (near the middle of the range of seventeen hundred to twenty-two hundred agreed to by presidents George W. Bush and Vladimir Putin in 2002), it will be necessary to maintain a reserve force several times that number. Lacking the ability to test aging weapons, an alternate warhead design should be maintained for each of the major systems in the inventory. Allowances should be made for weapons in the refurbishment pipeline, those that are temporarily disassembled for maintenance, or those in transit to or from their duty station. Finally, some weapons with special capabilities should be kept “just in case.”

Maximalists argue that it is foolish to dismantle thousands of weapons for no reason other than to say that we have done so. Our weapons represent a significant investment and should be maintained as a hedge against unforeseen contingencies. Other countries may or may not follow our lead in dismantlement.

Critics of the maximalist approach, myself included, note that it is wasteful to spread limited resources across thousands of weapons when only hundreds are required to deter aggression. The price tag associated with doing almost anything to a nuclear weapons system is at least a billion dollars, and that money would be better spent in improving the reliability and safety of a smaller set of weapons than in maintaining a huge arsenal in a warehouse.

The Moderate Position

I believe that the number of nuclear weapons we maintain should be based upon a careful analysis of military requirements with a hedge provided for unforeseen strategic contingencies. This I label the moderate position.

Fewer nuclear weapons will be required in the future because other means are available to achieve the same military objectives. Precision-delivered conventional weapons are capable of destroying many of the targets formerly assigned to nuclear weapons. Mobile missiles, submarines, aircraft, and many other types of targets do not require the explosive force of a nuclear weapon for their destruction. Nuclear weapons are required only for targets that would be very difficult or impossible to destroy with conventional explosives.

The exact number of weapons needed depends on our assessment of enemy assets and the level of confidence we would like to have in destroying them. Assuming that we maintain our counterforce strategy, we will most likely target only those enemy assets that could inflict grave damage on our country, our military forces, or our allies. These include nuclear and perhaps biological weapons, military command centers, and other locations of strategic significance.

Surveillance satellites can count large objects on the ground, including fixed missile silos and support facilities for nuclear submarines. We can thus count the number of things that we wish to hold at risk and size our force accordingly. As for the remainder of the adversary’s weapons, including aircraft-mounted bombs and cruise missiles, they are typically concentrated in a small number of hardened locations, each of which could be destroyed with one or a few weapons. Any adversary with ballistic missile submarines will surely have at least half of its fleet at sea during a time of crisis—shifting the military requirement from nuclear weapons to attack submarines that can hunt down and destroy the enemy’s missile carriers with conventional torpedoes. I took mobile missiles off the nuclear targeting list since they can be destroyed with conventional weapons assuming adequate intelligence.

The Russian Federation has by far the largest nuclear force of any potential adversary; it sets the requirement for numbers of weapons. Russia expects to have several hundred SS–27 missiles available in the near future and it will likely maintain some older ICBMs as a hedge. An American stockpile of five hundred to one thousand ready weapons would be sufficient to deter this force, that is, to make it impossible for Moscow to eliminate our weapons and avoid devastating retaliation following a first strike. Add to this an additional five hundred to one thousand weapons to cover the potential for system failure, the presence of weapons in the refurbishment pipeline, and some special weapons for unique applications, and the United States can still maintain a strong deterrent force with approximately one thousand to two thousand nuclear weapons—comparable to the number of weapons cited in the Moscow Treaty.

Having determined numbers, we can ask what types of weapons are required. A detailed analysis of potential targets shows that very few require more than ten kilotons for their destruction if the weapon is delivered with sufficient accuracy. Most of the remaining ones, all of which fall in the very hard target category, can be destroyed with a five-hundred-kiloton earth-penetrating weapon. If five hundred kilotons is not sufficient, it is unlikely that any explosion will suffice. A stockpile in which 90 percent of the weapons had ten kilotons of yield and the remaining 10 percent had five hundred kilotons is compatible with most future targeting requirements. Owing to the vulnerability of aircraft in reaching targets deep within enemy territory, all our weapons should be placed on ballistic missiles.

So far we have discussed weapons in terms of their explosive yield. Safety, security, reliability, and ease of manufacture are also critical to an effective stockpile. All the weapons in the current American nuclear arsenal were designed to maximize the yield-to-weight ratio, an economic consideration that enabled them to be carried on smaller missiles and aircraft. Since their designers anticipated that they would remain in the stockpile for no more than about twenty years, none were designed with long life in mind and none have a sufficient supply of spare parts. Only a handful were configured as earth-penetrating weapons that can hold very hard targets at risk. Finally, many have yields that are much greater than are required to satisfy future mission requirements. Our nuclear weapons stockpile is optimized for a threat that no longer exists.

Is there a role for manned bombers in the future of nuclear weapons? Perhaps, but only as a backup measure should an adversary develop an effective means of defeating ballistic missile warheads, a remote but nonetheless conceivable possibility. Manned bombers have an advantage in that they can be recalled right up until the time that the weapon is dropped, but they suffer from relative slowness compared to ballistic missiles and vulnerability to anti-aircraft weapons and fighters. It can take many hours for a bomber to fly from the United States to a distant target, compared to the thirty to sixty minutes required for a ballistic missile to cover the same distance. If a manned bomber (one containing a pilot) is to be maintained, it should be the stealthy B2 rather than the venerable but vulnerable B52. Unmanned bombers (versions of existing unmanned aerial vehicles) could also be used, although the possibility that they might lose contact with their controller and wander off on their own is a serious worry that should limit their use for nuclear missions.

Cruise missiles launched from bombers or submarines lack both the flexibility of bombers and the assured delivery of ballistic missiles, thus rendering them least suited to nuclear missions of the future. Powered by jet engines, they are slower than ballistic missiles but nevertheless fly on their own without intervention of a pilot. The possibility that a cruise missile might be shot down is very real, and should this happen, its warhead could be captured by an adversary. This might be the most powerful argument for their removal from the arsenal.

 

AS STRANGE AS it may seem during a time when we are busy dismantling nuclear weapons, we need to build new ones. We need weapons with lower yields, and weapons that can destroy WMD threats buried in reinforced structures and under mountains. And we need weapons that have modern safety and security features, those that make the weapon nearly impossible to detonate if it were to fall into the wrong hands.

When designing the nuclear stockpile of the future, especially one that has a tenuous connection to tested designs, it is important to include redundancy. Two types of weapons are required—a ten-kiloton and a five-hundred-kiloton warhead—but it would be wise to field two designs for each to avoid the possibility of single point failure of the entire fleet. Should one type of weapon be found to have a serious problem, it could be withdrawn for repair or replacement, leaving the other design to carry out the deterrent function.

It is imperative that a viable manufacturing capability be established if we are to maintain any credible nuclear deterrent. Too many special processes are involved in the construction of a nuclear weapon to replicate them on demand, especially in a time of crisis. A regular program of remanufacture, like the ones currently being followed by all the other nuclear weapons states, will help maintain skills and equipment. Regular international inspections can assure other countries that we are replacing weapons rather than increasing our total stockpile.

 

THE FUNDAMENTAL ROLE of nuclear weapons in assuring the security of the United States did not change with the end of the Cold War. They still serve as the ultimate defenders of our freedom, weapons that deter any state-level adversary from attacking our vital interests. However, nuclear weapons are only part of our future strategic posture. Ballistic missile defenses, while limited at present, will be effective against nuclear attacks launched by North Korea, Iran, or other new entrants to the nuclear arena. Advanced conventional weapons can replace nuclear weapons in many missions, lessening our reliance on the latter while maintaining military capability. Improved transparency and inspection treaties with other countries would reduce the need to maintain nuclear forces larger than required and could conceivably enable us to eliminate them altogether.

Nuclear weapons have been, since their very inception, instruments of contradiction—built with the hope that they would never be used, the ultimate engines of destruction designed to maintain the peace. The United States has the ability to transform the strategic future, reducing the threat of nuclear war while defending ourselves in a dangerous world. If we continue on our present course, we will find ourselves lingering in the shadow of the Cold War, unequipped to face a century that will demand new solutions to ever more complex problems.