7

The Offshore Balancers

I have reserved discussion of the American and British cases for a separate chapter because they might appear to provide the strongest evidence against my claim that great powers are dedicated to maximizing their share of world power. Many Americans certainly view their country as a truly exceptional great power that has been motivated largely by noble intentions, not balance-of-power logic. Even important realist thinkers such as Norman Graebner, George Kennan, and Walter Lippmann believe that the United States has frequently ignored the imperatives of power politics and instead acted in accordance with idealist values.¹ This same perspective is evident in the United Kingdom, which is why E. H. Carr wrote The Twenty Years’ Crisis in the late 1930s. He was warning his fellow citizens about their excessive idealism in foreign policy matters and reminding them that competition for power among states is the essence of international politics.²

There are three particular instances where it might seem that the United Kingdom and the United States passed up opportunities to gain power. First, it is usually said that the United States achieved great-power status in about 1898, when it won the Spanish-American War, which gave it control over the fate of Cuba, Guam, the Philippines, and Puerto Rico, and also when it began building a sizable military machine.³ By 1850, however, the United States already stretched from the Atlantic to the Pacific and, as was shown in Table 6.2, clearly possessed the economic wherewithal to become a great power and compete around the globe with Europe’s major powers. Yet it did not build powerful military forces between 1850 and 1898, and it made little effort to conquer territory in the Western Hemisphere, much less outside of it. Fareed Zakaria describes this period as a case of “imperial understretch.”⁴ The seeming failure of the United States to become a great power and pursue a policy of conquest in the second half of the nineteenth century might seem to contradict offensive realism.

Second, the United States was no ordinary great power by 1900. It had the most powerful economy in the world and it had clearly gained hegemony in the Western Hemisphere (see Table 6.2). Although neither of those conditions changed over the course of the twentieth century, the United States did not attempt to conquer territory in Europe or Northeast Asia or dominate those wealth-producing regions of the world. If anything, the United States has been anxious to avoid sending troops to Europe and Northeast Asia, and when it has been forced to do so, it has usually been anxious to bring them back home as soon as possible. This reluctance to expand into Europe and Asia might appear to contradict my claim that states try to maximize their relative power.

Third, the United Kingdom had substantially more potential power than any other European state during most of the nineteenth century. In fact, between 1840 and 1860, Britain controlled nearly 70 percent of European industrial might, almost five times more than France, its closest competitor (see Table 3.3). Nevertheless, the United Kingdom did not translate its abundant wealth into actual military might and attempt to dominate Europe. In a world where great powers are supposed to have an insatiable appetite for power and ultimately aim for regional hegemony, one might expect the United Kingdom to have acted like Napoleonic France, Wilhelmine Germany, Nazi Germany, and the Soviet Union and pushed hard to become Europe’s hegemon. But it did not.

The notion that the United Kingdom and the United States have not been power maximizers over much of the past two centuries is intuitively appealing at first glance. The fact is, however, both states have consistently acted as offensive realism would predict.

American foreign policy throughout the nineteenth century had one overarching goal: achieving hegemony in the Western Hemisphere. That task, which was motivated in good part by realist logic, involved building a powerful United States that could dominate the other independent states of North and South America and also prevent the European great powers from projecting their military might across the Atlantic Ocean. The American drive for hegemony was successful. Indeed, as emphasized earlier, the United States is the only state in modern times to have gained regional hegemony. This impressive achievement, not some purported noble behavior toward the outside world, is the real basis of American exceptionalism in the foreign policy realm.

There was no good strategic reason for the United States to acquire more territory in the Western Hemisphere after 1850, as it had already acquired a huge land mass over which its rule needed to be consolidated. Once that happened, the United States would be overwhelmingly powerful in the Americas. The United States paid little attention to the balance of power in Europe and Northeast Asia during the second half of the nineteenth century, not only because it was focused on gaining regional hegemony, but also because there were no potential peer competitors to worry about in either region. Finally, the United States did not build large and formidable military forces between 1850 and 1898 because there was no significant opposition to the growth of American power in those years.⁵ The United Kingdom kept few troops in North America, and the Native Americans possessed little military might. In essence, the United States was able to gain regional hegemony on the cheap.

The United States did not attempt to conquer territory in either Europe or Northeast Asia during the twentieth century because of the difficulty of projecting military forces across the Atlantic and Pacific Oceans against the great powers located in those regions.⁶ Every great power would like to dominate the world, but none has ever had or is likely to have the military capability to become a global hegemon. Thus, the ultimate goal of great powers is to achieve regional hegemony and block the rise of peer competitors in distant areas of the globe. In essence, states that gain regional hegemony act as offshore balancers in other regions. Nevertheless, those distant hegemons usually prefer to let the local great powers check an aspiring hegemon, while they watch from the sidelines. But sometimes this buck-passing strategy is not feasible, and the distant hegemon has to step in and balance against the rising power.

American military forces were sent to Europe and Northeast Asia at different times during the twentieth century, and the pattern of commitments follows the logic described above. In particular, whenever a potential peer competitor emerged in either of those regions, the United States sought to check it and preserve America’s unique position as the world’s only regional hegemon. As emphasized, hegemons are essentially status quo powers; the United States is no exception in this regard. Moreover, American policymakers tried to pass the buck to other great powers to get them to balance against the potential hegemon. But when that approach failed, the United States used its own military forces to eliminate the threat and restore a rough balance of power in the area so that it could bring its troops home. In short, the United States acted as an offshore balancer during the twentieth century to ensure that it remained the sole regional hegemon.

The United Kingdom, too, has never tried to dominate Europe, which is surprising, given that it used its military to forge a vast empire outside of Europe. Furthermore, the United Kingdom, unlike the United States, is a European power. Therefore, one might expect the mid-nineteenth-century United Kingdom to have translated its fabulous wealth into military might to make a run at gaining regional hegemony. The reason it did not do so, however, is basically the same as for the United States: the stopping power of water. Like the United States, the United Kingdom is an insular power that is physically separated from the European continent by a large body of water (the English Channel), which makes it virtually impossible for the United Kingdom to conquer and control all of Europe.

Still, the United Kingdom has consistently acted as an offshore balancer in Europe, as offensive realism would predict. Specifically, it has committed military forces to the continent when a rival great power threatened to dominate Europe and buck-passing was not a viable option. Otherwise, when there has been a rough balance of power in Europe, the British army has tended to stay off the continent. In sum, neither the United Kingdom nor the United States has attempted to conquer territory in Europe in modern times, and both have acted as the balancer of last resort in that region.⁷

This chapter will look more closely at the fit between offensive realism and the past behavior of the United Kingdom and the United States, focusing first on the American bid for regional hegemony in the nineteenth century. The subsequent two sections deal with the commitment of U.S. military forces to Europe and Northeast Asia in the twentieth century, while the section thereafter considers the United Kingdom’s role as an offshore balancer in Europe. Some broader implications of the previous analysis are considered in the final section.

THE RISE OF AMERICAN POWER (1800–1900)

It is widely believed that the United States was preoccupied with domestic politics for most of the nineteenth century and that it had little interest in international politics. But this perspective makes sense only if American foreign policy is defined as involvement in areas outside of the Western Hemisphere, especially Europe. For sure, the United States avoided entangling alliances in Europe during this period. Nevertheless, it was deeply concerned with security issues and foreign policy in the Western Hemisphere between 1800 and 1900. Indeed, the United States was bent on establishing regional hegemony, and it was an expansionist power of the first order in the Americas.⁸ Henry Cabot Lodge put the point well when he noted that the United States had “a record of conquest, colonization, and territorial expansion unequalled by any people in the nineteenth century.”⁹ Or the twentieth century, for that matter. When one considers America’s aggressive behavior in the Western Hemisphere, and especially the results, the United States seems well-suited to be the poster child for offensive realism.

To illustrate the expansion of U.S. military might, consider the U.S. strategic positions at the beginning and at the end of the nineteenth century. The United States was in a rather precarious strategic situation in 1800 (see Map 7.1). On the plus side, it was the only independent state in the Western Hemisphere, and it possessed all the territory between the Atlantic Ocean and the Mississippi River, save for Florida, which was under Spanish control. On the negative side, however, most of the territory between the Appalachian Mountains and the Mississippi River was sparsely populated by white Americans, and much of it was controlled by hostile Native tribes. Furthermore, Great Britain and Spain had huge empires in North America. Between them, they controlled almost all of the territory west of the Mississippi and most of the territory north and south of the United States. In fact, the population of the Spanish territory that eventually became Mexico was slightly larger than America’s population in 1800 (see Table 7.1).

By 1900, however, the United States was the hegemon of the Western Hemisphere. Not only did it control a huge swath of territory running from the Atlantic to the Pacific, but the European empires had collapsed and gone away. In their place were independent states such as Argentina, Brazil, Canada, and Mexico. But none of them had the population size or wealth to challenge the United States, which was the richest state on the planet by the late 1890s (see Table 6.2). Hardly anyone disagreed with Richard Olney, the American secretary of state, when he bluntly told the United Kingdom’s Lord Salisbury in his famous July 20, 1895, note, “Today the United States is practically sovereign on this continent, and its fiat is law upon the subjects to which it confines its interposition…. Its infinite resources combined with itsisolated position render it master of the situation and practically invulnerable as against any or all other powers.”¹⁰

The United States established regional hegemony in the nineteenth century by relentlessly pursuing two closely linked policies: 1) expanding across North America and building the most powerful state in the Western Hemisphere, a policy commonly known as “Manifest Destiny” and 2) minimizing the influence of the United Kingdom and the other European great powers in the Americas, a policy commonly known as the “Monroe Doctrine.”

Manifest Destiny

The United States started out in 1776 as a weak confederation cobbled together from the thirteen colonies strung along the Atlantic seaboard. The principal goal of America’s leaders over the next 125 years was to achieve the country’s so-called Manifest Destiny.¹¹ As noted, the United States had extended its control to the Mississippi River by 1800, although it did not yet control Florida. Over the next fifty years, the United States expanded westward across the continent to the Pacific Ocean. During the second half of the nineteenth century, the United States focused on consolidating its territorial gains and creating a rich and cohesive state.

The expansion of the United States between 1800 and 1850 involved five major steps (see Map 7.2). The huge Louisiana Territory on the western side of the Mississippi River was purchased from France in 1803 for $15 million. Napoleonic France had recently acquired that land from Spain, although it had been under French control from 1682 until 1762. Napoleon needed the proceeds from the sale to finance his wars in Europe. Furthermore, France was in no position to compete with the United Kingdom in North America, because the British had a superior navy that made it difficult for France to project its military might across the Atlantic Ocean. With the acquisition of the vast Louisiana Territory, the United States more than doubled its size. The United States made its next move in 1819 when it took Florida from Spain.¹² American leaders had been devising schemes since the early 1800s to acquire Florida, including a number of invasions by U.S. troops. Spain finally conceded the entire territory after American forces captured Pensacola in 1818.

The last three important acquisitions all occurred in the brief period between 1845 and 1848.¹³ Texas won its independence from Mexico in 1836 and shortly thereafter petitioned to join the United States. The petition was rejected, however, mainly because of congressional opposition to admitting Texas as a state in which slavery was legal.¹⁴ But that logjam was eventually broken, and Texas was annexed on December 29, 1845. Six months later, in June 1846, the United States settled a territorial dispute with the United Kingdom over the Oregon Territories, acquiring a large chunk of territory in the Pacific northwest. In early May 1846, a few weeks before the Oregon agreement, the United States declared war on Mexico and went on to conquer California and most of what is today the American southwest. In the space of two years, the United States had grown by 1.2 million square miles, or about 64 percent. The territorial size of the United States, according to the head of the Census Bureau, was now “nearly ten times as large as that of France and Britain combined; three times as large as the whole of France, Britain, Austria, Prussia, Spain, Portugal, Belgium, Holland, and Denmark together…[and] of equal extent with the Roman Empire or that of Alexander.”¹⁵

Expansion across the continent was pretty much complete by the late 1840s, although the United States did acquire a small portion of territory from Mexico in 1853 (the Gadsden Purchase) to smooth out the border between the two countries, and the United States purchased Alaska from Russia in 1867. However, the United States did not acquire all the territory it wanted. In particular, it aimed to conquer Canada when it went to war with the United Kingdom in 1812, and many of its leaders continued to covet Canada throughout the nineteenth century.¹⁶ There was also pressure to expand southward into the Caribbean, where Cuba was considered the prize target.¹⁷ Nevertheless, expansion to the north and south never materialized, and the United States instead expanded westward toward the Pacific Ocean, building a huge territorial state in the process.¹⁸

The United States had little need for more territory after 1848—at least for security reasons. So its leaders concentrated instead on forging a powerful state inside its existing borders. This consolidation process, which was sometimes brutal and bloody, involved four major steps: fighting the Civil War to eliminate slavery and the threat of dissolution of the union; displacing the Natives who controlled much of the land that the United States had recently acquired; bringing large numbers of immigrants to the United States to help populate its vast expanses of territory; and building the world’s largest economy.

During the first six decades of the nineteenth century, there was constant friction between North and South over the slavery issue, especially as it applied to the newly acquired territories west of the Mississippi. Indeed, the issue was so poisonous that it threatened to tear apart the United States, a result that would have had profound consequences for the balance of power in the Western Hemisphere. Matters finally came to a head in 1861, when the Civil War broke out. The North, which was fighting to hold the United States together, fared badly at first but eventually recovered and won a decisive victory. Slavery was quickly ended in all parts of the United States, and despite the ill will generated by the war, the country emerged a coherent whole that has since remained firmly intact. Had the Confederacy triumphed, the United States would not have become a regional hegemon, since there would have been at least two great powers in North America. This situation would have created opportunities for the European great powers to increase their political presence and influence in the Western Hemisphere.¹⁹

As late as 1800, Native American tribes controlled huge chunks of territory in North America that the United States would have to conquer if it hoped to fulfill Manifest Destiny.²⁰ The Natives hardly stood a chance of stopping the United States from taking their land. The Natives had a number of disadvantages, but most important, they were greatly outnumbered by white Americans and their situation only grew worse with time. In 1800, for example, about 178,000 Natives lived within the borders of the United States, which then extended to the Mississippi River.²¹ At the same time, the population of the United States was roughly 5.3 million (see Table 7.1). Not surprisingly, the U.S army had little trouble crushing the Natives east of the Mississippi, taking their land, and pushing many of them west of the Mississippi in the first few decades of the nineteenth century.²²

By 1850, when the present borders of the continental United States were largely in place, there were about 665,000 Native Americans living inside them, of whom roughly 486,000 lived west of the Mississippi. The population of the United States, however, had grown to nearly 23.2 million by 1850. Not surprisingly, then, small and somewhat inept U.S. army units were able to rout the Natives west of the Mississippi and take their land in the second half of the nineteenth century.²³ Victory over the Natives was complete by 1900. They were living on a handful of reservations and their total population had shrunk to about 456,000, of whom 299,000 lived west of the Mississippi. By that time the population of the United States had reached 76 million.

The population of the United States more than tripled during the second half of the nineteenth century, in good part because massive numbers of European immigrants crossed the Atlantic. Indeed, between 1851 and 1900, approximately 16.7 million immigrants came to the United States.²⁴ By 1900, 34.2 percent of all 76 million Americans were either born outside the United States or had at least one parent born in a foreign land.²⁵ Many of those immigrants came looking for jobs, which they found in the expanding U.S. economy. At the same time, however, they contributed to the strength of that economy, which grew by leaps and bounds in the latter part of the nineteenth century. Consider, for example, that the United Kingdom was the world’s wealthiest country in 1850, with roughly four times the industrial might of the United States. Only fifty years later, however, the United States was the wealthiest country on the globe and had more than 1.6 times the industrial might of the United Kingdom (see Table 6.2).

The United Kingdom and the United States ended their long rivalry in North America during the early years of the twentieth century. In effect, the United Kingdom retreated across the Atlantic Ocean and left the United States to run the Western Hemisphere. A commonplace explanation for this rapprochement is that the United Kingdom had to consolidate its military forces in Europe to check a rising Germany, so it cut a deal with the United States, which was accommodating because it had a vested interest in getting the British out of North America, as well as having them maintain the balance of power in Europe.²⁶ There is much truth in this line of argument, but there is an even more important reason why the British-American rivalry ended in 1900: the United Kingdom no longer had the power to challenge the United States in the Western Hemisphere.²⁷

The two principal indicators of potential military might are population size and industrial might, and the United States was far ahead of the United Kingdom on both indicators by 1900 (see Table 7.2). Furthermore, the United Kingdom had to project power across the Atlantic Ocean into the Western Hemisphere, whereas the United States was physically located there. The U.S.-U.K. security competition was over. Even if there had been no German threat in the early twentieth century, the United Kingdom would almost surely have abandoned the Western Hemisphere to its offspring, which had definitely come of age by then.

The Monroe Doctrine

American policymakers in the nineteenth century were not just concerned with turning the United States into a powerful territorial state, they were also deeply committed to getting the European powers out of the Western Hemisphere and keeping them out.28 Only by doing that could the United States make itself the region’s hegemon, highly secure from great-power threats. As the United States moved across North America, it gobbled up territory that previously had belonged to the United Kingdom, France, and Spain, thus weakening their influence in the Western Hemisphere. But it also used the Monroe Doctrine for that same purpose.

The Monroe Doctrine was laid out for the first time in President James Monroe’s annual message to Congress on December 2, 1823. He made three main points about American foreign policy.²⁹ First, Monroe stipulated that the United States would not get involved in Europe’s wars, in keeping with George Washington’s advice in his famous “farewell address” (this policy certainly has not been followed in the twentieth century).³⁰ Second, he put the European powers on notice that they could not acquire new territory in the Western Hemisphere to increase the size of their already considerable empires. “The American Continents,” the president said, “are henceforth not to be considered as subjects for future colonization by any European Power.” But the policy did not call for dismembering the European empires already established in the Western Hemisphere.³¹ Third, the United States wanted to make sure that the European powers did not form alliances with the independent states of the Western Hemisphere or control them in any way. Thus, Monroe stated that “with the Governments who have declared their independence and maintained it…we could not view any interposition for the purpose of oppressing them, or controlling in any other manner their destiny, by any European power in any other light than as the manifestation of an unfriendly disposition towards the United States.”

It is understandable that the United States would worry in the early 1800s about further European colonization. The United Kingdom, for example, was a powerful country with a rich history of empire-building around the globe, and the United States was not powerful enough at the time to check the British everywhere in the Western Hemisphere. Indeed, the United States probably did not have sufficient military might to enforce the Monroe Doctrine in the first decades after it was enunciated. Nevertheless, this problem proved illusory, as the European empires shrivelled away over the course of the nineteenth century and no new ones rose in their place.³² The United States actually had little to do with the collapse of those empires, which were wrecked mainly from within by nationalism.³³ Brazilians, Canadians, and Mexicans, like the American colonists in 1776, did not want Europeans controlling their politics, so they followed the U.S. example and became independent states.

The real danger that the United States faced in the nineteenth century—and continued to face in the twentieth century—was the possibility of an anti-American pact between a European great power and a state in the Western Hemisphere. An alliance like that might ultimately be powerful enough to challenge U.S. hegemony in the Americas, which would adversely affect the country’s security. Thus, when Secretary of State Olney sent his famous note to Lord Salisbury in the summer of 1895, he emphasized that “the safety and welfare of the United States are so concerned with the maintenance of the independence of every American state as against any European power as to justify and require the interposition of the United States whenever that independence is endangered.”³⁴

The United States was able to deal with this threat when it arose during the nineteenth century. For example, France placed an emperor on the throne of Mexico during the American Civil War, but French and Mexican troops together were not a serious threat to the United States, even though it was fighting a bloody internal conflict. When that war ended, the nationalist forces of Benito Juarez and the United States army forced France to withdraw its troops from Mexico. The United States grew more powerful between 1865 and 1900, making it increasingly difficult for any European great power to forge an anti-American alliance with an independent state in the Western Hemisphere. Nevertheless, the problem has not gone away. In fact, the United States had to deal with it three times in the twentieth century: German involvement in Mexico during World War I, German designs on South America during World War II, and the Soviet Union’s alliance with Cuba during the Cold War.³⁵

The Strategic Imperative

The stunning growth of the United States in the hundred years after 1800 was fueled in good part by realist logic.³⁶ “The people of the United States have learned,” Olney wrote at the end of the nineteenth century, that “the relations of states to each other depend not upon sentiment nor principle, but upon selfish interest.”³⁷ Moreover, American leaders understood that the more powerful their country was, the more secure it would be in the dangerous world of international politics. President Franklin Pierce made the point in his inaugural address on March 4, 1853: “It is not to be disguised that our attitude as a nation and our position on the globe render the acquisition of certain possessions not within our jurisdiction eminently important for our protection.”³⁸

Of course, Americans had other motives for expanding across the continent. For example, some had a powerful sense of ideological mission.³⁹ They believed that the United States had created a virtuous republic that was unprecedented in world history and that its citizens had a moral duty to spread its values and political system far and wide. Others were driven by the promise of economic gain, a powerful motor for expansion.⁴⁰ These other motives, however, did not contradict the security imperative; in fact, they usually complemented it.⁴¹ This was especially true for the economic motive: because economic might is the foundation of military might, any actions that might increase the relative wealth of the United States would also enhance its prospects for survival. On idealism, there is no question that many Americans fervently believed that expansion was morally justified. But idealist rhetoric also provided a proper mask for the brutal policies that underpinned the tremendous growth of American power in the nineteenth century.⁴²

Balance-of-power politics had a rich history in the Western Hemisphere even before the United States declared its independence in 1776.⁴³ In particular, the British and the French waged an intense security competition in North America during the middle of the eighteenth century, including the deadly Seven Years’ War (1756–63). Moreover, the United States ultimately achieved its independence by going to war against Great Britain and making an alliance with France, Britain’s arch-rival. James Hutson has it right when he says, “The world the American Revolutionary leaders found themselves in was a brutal, amoral cockpit…. [It] was, above all, a world in which power was king.”⁴⁴ Thus, the elites who managed U.S. national security policy in the decades after the country’s independence were steeped in realist thinking.

The politics of the Western Hemisphere in 1800 provided good reasons for those elites to continue thinking in terms of the balance of power. The United States was still operating in a dangerous neighborhood. The British and Spanish empires surrounded it on three sides, making fear of encirclement a common theme among American policymakers, who also worried that Napoleonic France, the most powerful state in Europe, would try to build a new empire in North America. Of course, the French empire never materialized, and indeed, France sold the huge Louisiana Territory to the United States in 1803.

Nevertheless, the Europeans, especially the British, were determined to do what they could to contain the United States and prevent it from further expanding its borders.⁴⁵ The United Kingdom actually succeeded at stopping the United States from conquering Canada in the War of 1812. The United Kingdom had few good options for preventing the westward expansion of the United States, but it did form brief alliances with the Native Americans of the Great Lakes region between 1807 and 1815, and later with Texas when it was briefly an independent state.⁴⁶ But these efforts never seriously threatened to stop the United States from reaching the Pacific Ocean.

In fact, it appears that any move a European state made to contain the United States had the opposite effect: it strengthened the American imperative to expand. For example, Europeans began speaking openly in the early 1840s about the need to maintain a “balance of power” in North America, a euphemism for containing further American expansion while increasing the relative power of the European empires.⁴⁷ The subject was broached before the United States expanded westward beyond the Louisiana Territory. Not surprisingly, it immediately became a major issue in U.S. politics, although there was not much disagreement among Americans on the issue. President James Polk surely spoke for most Americans when he said that the concept of a balance of power “cannot be permitted to have any application to the North American continent, and especially to the United States. We must ever maintain the principle that the people of this continent alone have the right to decide their own destiny.”⁴⁸ Shortly after Polk spoke on December 2, 1845, Texas was incorporated into the United States, soon to be followed by the Oregon Territories, California, and the other land taken from Mexico in 1848.

The historian Frederick Merk succinctly summarizes American security policy in the nineteenth century when he writes, “The chief defense problem was the British, whose ambition seemed to be to hem the nation in. On the periphery of the United States, they were the dangerous potential aggressors. The best way to hold them off was to acquire the periphery. This was the meaning of the Monroe Doctrine in the age of Manifest Destiny.”⁴⁹

THE UNITED STATES AND EUROPE, 1900–1990

Offensive realism predicts that the United States will send its army across the Atlantic when there is a potential hegemon in Europe that the local great powers cannot contain by themselves. Otherwise, the United States will shy away from accepting a continental commitment. The movement of American forces into and out of Europe between 1900 and 1990 fits this general pattern of offshore balancing. A good way to grasp the broad outlines of American military policy toward Europe is to describe it during the late nineteenth century and in five distinct periods of the twentieth century.

The United States gave hardly any thought to sending an army to Europe between 1850 and 1900, in part because staying out of Europe’s wars was deeply ingrained in the American psyche by 1850. Presidents George Washington and James Monroe, among others, had made sure of that.⁵⁰ Furthermore, the United States was concerned primarily with establishing hegemony in the Western Hemisphere during the second half of the nineteenth century. But most important, the United States did not contemplate sending troops across the Atlantic because there was no potential hegemon in Europe at that time. Instead, there was a rough balance of power on the continent.⁵¹ France, which made a run at hegemony between 1792 and 1815, was on the decline throughout the nineteenth century, while Germany, which would become a potential hegemon in the early twentieth century, was not powerful enough to overrun Europe before 1900. Even if there had been an aspiring European hegemon, however, the United States surely would have adopted a buck-passing strategy, hoping that the other great powers in Europe could contain the threat.

The first period in the twentieth century covers the time from 1900 to April 1917. It was apparent in the early years of the new century that Germany was not simply the most powerful state in Europe but was increasingly threatening to dominate the region.⁵² In fact, Germany precipitated a number of serious diplomatic crises during that period, culminating in the outbreak of World War I on August 1, 1914. Nevertheless, no American troops were sent to Europe to thwart German aggression. The United States pursued a buck-passing strategy instead, relying on the Triple Entente—the United Kingdom, France, and Russia—to contain Germany.⁵³

The second period runs from April 1917 until 1923; it covers American participation in World War I, which was the first time in its history that the United States sent troops to fight in Europe. The United States declared war against Germany on April 6, 1917, but was able to send only four divisions to France by the end of that year.⁵⁴ However, large numbers of American troops started arriving on the continent in early 1918, and by the time the war ended on November 11, 1918, there were about two million American soldiers stationed in Europe and more on their way. Indeed, General John Pershing, the head of the American Expeditionary Force, expected to have more than four million troops under his command by July 1919. Most of the troops sent to Europe were brought home soon after the war ended, although a small occupation force remained in Germany until January 1923.⁵⁵

The United States entered World War I in good part because it thought that Germany was gaining the upper hand on the Triple Entente and was likely to win the war and become a European hegemon.⁵⁶ America’s buck-passing strategy, in other words, was unraveling after two and a half years of war. The Russian army, which had been badly mauled in almost every engagement it had with the German army, was on the verge of disintegration by March 12, 1917, when revolution broke out and the tsar was removed from power.⁵⁷ The French army was also in precarious shape, and it suffered mutinies in May 1917, shortly after the United States entered the war.⁵⁸ The British army was in the best shape of the three allied armies, mainly because it spent the first two years of the war expanding into a mass army and thus had not been bled white like the French and Russian armies. The United Kingdom was nevertheless in desperate straits by April 1917, because Germany had launched an unrestricted submarine campaign against British shipping in February 1917 that was threatening to knock the United Kingdom out of the war by the early fall.⁵⁹ Consequently, the United States was forced to enter the war in the spring of 1917 to bolster the Triple Entente and prevent a German victory.⁶⁰

The third period covers the years from 1923 to the summer of 1940. The United States committed no forces to Europe during those years. Indeed, isolationism was the word commonly used to describe American policy during the years between the world wars.⁶¹ The 1920s and early 1930s were relatively peaceful years in Europe, mainly because Germany remained shackled by the strictures of the Versailles Treaty. But Adolf Hitler came to power on January 30, 1933, and soon thereafter Europe was in turmoil again. By the late 1930s, American policymakers recognized that Nazi Germany was a potential hegemon and that Hitler was likely to attempt to conquer Europe. World War II began on September 1, 1939, when Germany attacked Poland and the United Kingdom and France responded by declaring war against Germany. However, the United States made no serious move toward a continental commitment when the war broke out. As in World War I, it initially relied on Europe’s other great powers to contain the German threat.⁶²

The fourth period covers the five years from the summer of 1940, when Germany decisively defeated France and sent the British army back home via Dunkirk, until the European half of World War II ended in early May 1945. American policymakers had expected the British and French armies to stop a Wehrmacht offensive on the western front and force a protracted war of attrition that would sap Germany’s military might.⁶³ Josef Stalin expected the same outcome, but the Wehrmacht shocked the world by winning a quick and decisive victory in France.⁶⁴ With this victory, Germany was well-positioned to threaten the United Kingdom.

More important, however, Hitler could use most of his army to invade the Soviet Union, because he had no western front to worry about. It was widely believed in the United Kingdom and the United States that the Wehrmacht was likely to defeat the Red Army and establish hegemony in Europe.⁶⁵ After all, Germany had knocked Russia out of World War I, and in that case Germany was fighting a two-front war and had substantially more divisions fighting against the British and French armies than against the Russian army.⁶⁶ This time the Germans would be essentially fighting a one-front war. Also, Stalin’s purge of the Red Army between 1937 and 1941 had markedly reduced its fighting power. This weakness was on display in the winter of 1939–40, when the Red Army had trouble defeating the badly outnumbered Finnish army. In short, there was ample reason to think in the summer of 1940 that Germany was on the threshold of dominating continental Europe.

The collapse of France precipitated a dramatic change in American thinking about a continental commitment.⁶⁷ Suddenly there was widespread support for providing substantial aid to the United Kingdom, which now stood alone against Germany, and for preparing the American military for a possible war with Germany. By early fall of 1940, public opinion polls showed that for the first time since Hitler came to power, a majority of Americans believed it was more important to ensure that the United Kingdom defeat Germany than to avoid a European war.⁶⁸ The U.S. Congress also drastically increased defense spending in the summer of 1940, making it possible to start building an expeditionary force for Europe: on June 30, 1940, the size of the American army was 267,767; one year later, roughly five months before Pearl Harbor, the strength of the army had grown to 1,460,998.⁶⁹

Furthermore, with the passage of the Lend-Lease Act on March 11, 1941, the United States began sending large amounts of war material to the British. It is hard to disagree with Edward Corwin’s claim that this step was “a qualified declaration of war” against Germany.⁷⁰ During the summer and fall of 1941, the United States became more deeply involved in helping the United Kingdom win its fight with Germany, reaching the point in mid-September where President Franklin Roosevelt instructed the U.S. navy to fire on sight at German submarines in the Atlantic Ocean. The United States did not formally go to war against Germany, however, until December 11, 1941, when Hitler declared war against the United States four days after the Japanese attack at Pearl Harbor. American troops did not set foot on the European continent until September 1943, when they landed in Italy.⁷¹

The fifth period covers the Cold War, which ran from the summer of 1945 to 1990. The United States planned to bring most of its troops home immediately after World War II ended, leaving just a small occupation force behind to police Germany for a few years, as it had after World War I.⁷² By 1950, there were only about 80,000 American troops left in Europe, and they were mainly involved with occupation duty in Germany.⁷³ But as the Cold War intensified in the late 1940s, the United States formed the North Atlantic Treaty Organization (1949) and eventually made a commitment to remain in Europe and substantially increase its fighting forces on the continent (1950). By 1953, 427,000 American troops were stationed in Europe, which was the high-water mark for the Cold War. The United States also deployed about seven thousand nuclear weapons on European soil during the 1950s and early 1960s. Although there was some variation over time in American troop levels in Europe, the number never dipped below 300,000.

The United States reluctantly kept military forces in Europe after World War II because the Soviet Union controlled the eastern two-thirds of the continent and it had the military might to conquer the rest of Europe.⁷⁴ There was no local great power that could contain the Soviet Union: Germany was in ruins and neither France nor the United Kingdom had the military wherewithal to stop the mighty Red Army, which had just crushed the same Wehrmacht that had easily defeated the British and French armies in 1940. Only the United States had sufficient military power to prevent Soviet hegemony after 1945, so American troops remained in Europe throughout the Cold War.

THE UNITED STATES AND NORTHEAST ASIA, 1900–1990

The movement of American troops across the Pacific in the twentieth century follows the same pattern of offshore balancing that we saw at work in Europe. A good way to understand U.S. military policy toward Northeast Asia is to divide the years from 1900 to 1990 into four periods, and describe the practice in each of them.

The first period covers the initial three decades of the twentieth century, during which there was no large-scale commitment of American forces to Northeast Asia.⁷⁵ There were, however, small contingents of U.S. military forces in Asia during this period. The United States maintained a small contingent of forces in the Philippine Islands,⁷⁶ and it also sent five thousand troops to China in 1900 to help put down the Boxer Rebellion and maintain the infamous “Open Door” policy. As John Hay, the American secretary of state, candidly noted at the time, “the inherent weakness of our position is this: we do not want to rob China ourselves, and our public opinion will not permit us to interfere, with an army, to prevent others from robbing her. Besides, we have no army. The talk of the papers about ‘our preeminent moral position giving us the authority to dictate to the world’ is mere flap-doodle.”⁷⁷ A contingent of approximately one thousand U.S. soldiers was deployed to Tientsin, China, from January 1912 to March 1938. Finally, U.S. navy gunboats were on patrol in the region during this period.⁷⁸

The United States did not send a large army to Northeast Asia because there was no potential hegemon in the area. China played an important role in the region’s politics, but it was not a great power and it hardly threatened to dominate Northeast Asia. The United Kingdom and France were important actors in Asia in the early twentieth century, but they were interlopers from a distant continent, with all the power-projection problems that role entails. Moreover, they were concerned with containing Germany during most of this period, so most of their attention was focused on Europe at the expense of Northeast Asia. Japan and Russia were candidates for potential hegemon in Northeast Asia, because each was a great power located in the region. But neither fit the bill.

Japan possessed the most formidable army in the region between 1900 and 1930. It soundly defeated the Russian army in the Russo-Japanese War (1904–5).⁷⁹ Russia’s army went from bad to worse during World War I, finally disintegrating in 1917. The newly created Red Army was essentially a paper tiger throughout the 1920s. Meanwhile, the Japanese army remained an impressive fighting force.⁸⁰ But Japan was not a potential hegemon because Russia was the wealthiest state in the region. For example, Russia controlled 6 percent of world industrial might in 1900, while Japan did not even control 1 percent (see Table 6.2). By 1910, Russia’s share had shrunk to 5 percent, while Japan’s share had grown to 1 percent—still a substantial Russian lead. Italy was actually Japan’s closest economic competitor in these years. Japan briefly overtook the Soviet Union in 1920—2 percent vs. 1 percent—but that was only because the Soviet Union was in the midst of a catastrophic civil war. By 1930, Russia controlled 6 percent of world industrial might, while Japan controlled 4 percent. In short, Japan was not powerful enough during the early decades of the twentieth century to drive for supremacy in Northeast Asia.

The second period covers the decade of the 1930s, when Japan went on a rampage on the Asian mainland. Japan conquered Manchuria in 1931, which it turned into the puppet state of Manchukuo. In 1937, Japan went to war against China; its aim was to conquer northern China and key Chinese coastal regions. Japan also initiated a series of border conflicts with the Soviet Union in the late 1930s with the clear intention of making territorial gains at the expense of Moscow. Japan seemed bent on dominating Asia.

The United States did not move troops to Asia in the 1930s because, Japan’s grand ambitions notwithstanding, it was not a potential hegemon and China, France, the Soviet Union, and the United Kingdom were capable of containing the Japanese army. The Soviet Union actually gained a significant power advantage over Japan during that decade, mainly because the Soviet Union underwent rapid industrialization after the first Five-Year Plan was put into effect in 1928. The Soviet Union’s share of world wealth climbed from 6 percent in 1930 to 13 percent in 1940, while Japan’s went from 4 percent to 6 percent over the same period (see Table 6.2). Furthermore, the Red Army developed into an efficient fighting force in the 1930s. Indeed, it played a critical role in containing Japan, inflicting defeats on the Japanese army in 1938 and 1939.⁸¹

The United Kingdom and China also helped check Japan in the 1930s. The United Kingdom was actually inclined to pull most of its forces out of Asia and strike a deal with Japan in the late 1930s, so that it could concentrate on containing Nazi Germany, which was a more direct and dangerous threat than was Japan.⁸² But the United States, playing the role of the buck-passer, told the United Kingdom that any diminution of its force levels in Asia was unacceptable, and that the United Kingdom would have to remain engaged in Asia and balance against Japan. Otherwise, the United States might not help it deal with the growing German threat in Europe. The British stayed in Asia. Although China was not a great power at the time, it managed to pin down the Japanese army in a costly and protracted war that Japan was unable to win.⁸³ In fact, Japan’s experience in China between 1937 and 1945 bears considerable resemblance to the American experience in Vietnam (1965–72) and the Soviet experience in Afghanistan (1979–89).

The third period covers the years between 1940 and 1945, when Japan suddenly became a potential hegemon because of events in Europe. The fall of France in June 1940 and the German invasion of the Soviet Union in June 1941 funadamentally altered the balance of power in Northeast Asia. Germany’s quick and decisive victory over France in the late spring of 1940 greatly reduced, if not eliminated, French influence on Japanese behavior in Asia. Indeed, the defeat of France as well as of the Netherlands left their empires in Southeast Asia vulnerable to Japanese attack. With France out of the war, the United Kingdom stood alone against Nazi Germany in the west. But the British army was in shambles after Dunkirk and the Luftwaffe started pounding British cities in mid-July 1940. The United Kingdom also had to contend with fascist Italy in and around the Mediterranean. In short, the British were hanging on for dear life in Europe and therefore could contribute little to containing Japan in Asia.

Nevertheless, the United States made no move to send troops to Asia in 1940, largely because 1) Japan was bogged down in its war with China, and 2) the Soviet Union, which was not involved in the European half of the conflict at that point, was a formidable balancing force against Japan. That situation changed drastically when Germany invaded the Soviet Union on June 22, 1941. Over the next six months, the Wehrmacht inflicted a series of staggering defeats on the Red Army. It appeared likely by the late summer of 1941 that the Soviet Union would collapse as France had the year before. Japan would then be well-positioned to establish hegemony in Northeast Asia, because it would be the only great power left in the region. In effect, the European half of World War II was creating a power vacuum in Asia that Japan was ready to fill.

American policymakers were especially worried that Japan would move northward and attack the Soviet Union from the rear, helping Germany finish off the Soviet Union. Germany would then be the hegemon in Europe, while in Northeast Asia, only China would stand in the way of Japanese hegemony. As offensive realism would predict, the United States began moving military forces to Asia in the fall of 1941 to deal with the Japanese threat.⁸⁴ Shortly thereafter, Japan attacked the United States at Pearl Harbor, guaranteeing that massive American military forces would move across the Pacific for the first time ever. Their aim would be to crush Japan before it achieved regional hegemony.

The fourth period covers the Cold War (1945–90). The United States maintained military forces in Asia after World War II for essentially the same reason it accepted a continental commitment in Europe: the Soviet Union, which scored a stunning military victory in Manchuria against Japan’s Kwantung Army in the final days of World War II, was a potential hegemon in Northeast Asia as well as in Europe, and there were no local great powers to contain it.⁸⁵ Japan was in ruins and China, which was not a great power anyway, was in the midst of a brutal civil war. The United Kingdom and France were in no position to check the Soviet Union in Europe, much less in Asia. So the United States had little choice but to assume the burden of containing the Soviet Union in the Far East.⁸⁶ The United States ended up fighting two bloody wars in Asia during the Cold War, while it fired not a shot in Europe.

BRITISH GRAND STRATEGY, 1792–1990

Like the United States, the United Kingdom is separated from the European continent by a substantial body of water, and it, too, has a history of sending troops to the continent. The United Kingdom has also followed an offshore balancing strategy.⁸⁷ As Sir Eyre Crowe noted in his famous 1907 memorandum about British security policy, “It has become almost an historical truism to identify England’s secular policy with the maintenance of this [European] balance by throwing her weight…on the side opposed to the political dictatorship of the strongest single state.”⁸⁸ Moreover, the United Kingdom has consistently tried to get other great powers to bear the burden of containing potential European hegemons while it remains on the sidelines for as long as possible. Lord Bolingbroke succinctly summarized British thinking about when to commit to the continent in 1743: “We should take few engagements on the continent, and never those of making a land war, unless the conjecture be such, that nothing less than the weight of Britain can prevent the scales from being quite overturned.”⁸⁹ This commitment to buck-passing explains in good part why other states in Europe have referred to the United Kingdom as “Perfidious Albion” over the past few centuries.

Let us consider British military policy toward the continent from 1792, when the French Revolutionary and Napoleonic Wars started, until the Cold War ended in 1990.⁹⁰ Those two centuries can be roughly divided into six periods.

The first period runs from 1792 until 1815 and covers the French Revolutionary and Napoleonic Wars in their entirety. France was by far the most powerful state on the continent during this period, and it was bent on dominating Europe.⁹¹ France was an especially aggressive and formidable great power after Napoleon took over the reigns of power in late 1799. In fact, by the time Napoleon’s armies entered Moscow in the fall of 1812, France controlled most of continental Europe. The French drive for hegemony was ultimately thwarted, however, and the British army played an important role in bringing down Napoleon. Great Britain deployed a small army to the continent in 1793, but it was forced to remove those forces in 1795 when the coalition arrayed against France collapsed. Britain placed another army in Holland in August 1799, but it was defeated by and surrendered to the French army within two months. In 1808, the United Kingdom placed an army in Portugal and Spain that eventually helped inflict a decisive defeat on the large French forces in Spain. That same British army helped deliver the final blow against Napoleon at Waterloo (1815).

The second period runs from 1816 to 1904, when the United Kingdom adopted a policy commonly referred to as “splendid isolation.”⁹² It made no continental commitment during this period, despite the numerous great-power wars raging on the continent. Most important, the United Kingdom did not intervene in either the Austro-Prussian War (1866) or the Franco-Prussian War (1870–71), which led to the creation of a unified Germany. The United Kingdom sent no troops to Europe during those nine decades because there was a rough balance of power on the continent.⁹³ France, which was a potential hegemon from 1793 until 1815, lost relative power over the course of the nineteenth century, while Germany, which would become the next potential hegemon in the early twentieth century, was not yet powerful enough to dominate Europe. In the absence of a potential hegemon, the United Kingdom had no good strategic reason to move troops to the European mainland.

The third period runs from 1905 to 1930 and was dominated by the United Kingdom’s efforts to contain Wilhelmine Germany, which emerged as a potential hegemon in the early twentieth century.⁹⁴ It was apparent by 1890 that Germany, with its formidable army, large population, and dynamic industrial base, was rapidly becoming Europe’s most powerful state. Indeed, France and Russia formed an alliance in 1894 to contain the growing threat located between them. The United Kingdom would have preferred to let France and Russia deal with Germany. But it was clear by 1905 that they could not do the job alone and would need British help. Not only were the power differentials between Germany and its continental rivals continuing to widen in Germany’s favor, but Russia suffered a major military defeat in the Russo-Japanese War (1904–5), which left its army in terrible shape and in no condition to engage the German army. Finally, Germany initiated a crisis with France over Morocco in March 1905, which was designed to isolate France from the United Kingdom and Russia, thus leaving Germany in a position to dominate Europe.

In response to this deteriorating strategic environment, the United Kingdom allied with France and Russia between 1905 and 1907, forming the Triple Entente. In essence, Britain made a continental commitment to deal with the threat of a German hegemon. When World War I broke out on August 1, 1914, the United Kingdom immediately sent an expeditionary force to the continent to help the French army thwart the Schlieffen Plan. As the war progressed, the size of the British expeditionary force grew, until it was the most formidable Allied army by the summer of 1917. It then played the main role in defeating the German army in 1918.⁹⁵ Most of the British army exited the continent shortly after the war ended; a small occupation force remained in Germany until 1930.⁹⁶

The fourth period runs from 1930 to the summer of 1939 and covers the years when the United Kingdom pursued a Europe policy commonly referred to as “limited liability.” It made no continental commitment in the early 1930s, because Europe was relatively peaceful and there was a rough balance of power in the region. After Hitler came to power in 1933 and began to rearm Germany, the United Kingdom made no move to commit ground forces to fight on the continent. Instead, after much debate, it decided in December 1937 to pass the buck to France to contain Germany. British policymakers eventually realized, however, that France alone did not have the military might to deter Hitler, and that in the event of a war, the United Kingdom would have to send troops to fight Nazi Germany, as it had done against Napoleonic France and Wilhelmine Germany.

The United Kingdom finally accepted a continental commitment on March 31, 1939, which marks the beginning of the fifth period. Specifically, it committed itself to fight with France against Germany if the Wehrmacht attacked Poland. A week later the United Kingdom gave the same guarantee to Greece and Romania. When World War II broke out five months later, British troops were promptly sent to France, as they had been in World War I. Although the British army was pushed off the continent at Dunkirk in June 1940, it returned in September 1943 when it landed with the American army in Italy. British forces also landed at Normandy in June 1944 and eventually fought their way into Germany. This period ended with the surrender of Germany in early May 1945.

The final period runs from 1945 to 1990 and covers the Cold War.⁹⁷ With the end of World War II, Britain had planned to move its military forces off the continent after a brief occupation of Germany. However, the emergence of the Soviet threat, the fourth potential hegemon to confront Europe in 150 years, forced the United Kingdom to accept a continental commitment in 1948. British troops, along with American troops, remained on the central front for the duration of the Cold War.

CONCLUSION

In sum, both the United Kingdom and the United States have consistently acted as offshore balancers in Europe. Neither of these insular great powers has ever tried to dominate Europe. It is also clear that American actions in Northeast Asia fit the same pattern. All of this behavior, as well as the U.S. drive for hegemony in the Western Hemisphere during the nineteenth century, corresponds with the predictions of offensive realism.

This chapter raises two issues that bear mentioning. First, insular Japan’s conquest of large amounts of territory on the Asian mainland in the first half of the twentieth century might seem to contradict my claim that the stopping power of water made it almost impossible for the United Kingdom in the nineteenth century and the United States in the twentieth century to conquer territory on the European continent. After all, if Japan was able to project power across the seas separating it from the Asian continent, why is it that the United Kingdom and the United States could not do likewise in Europe?

The answer is that the Asian and European mainlands were different kinds of targets during the periods under discussion. In particular, the European continent has been populated by formidable great powers over the past two centuries, and those states have had both the incentive and the wherewithal to prevent the United Kingdom and the United States from dominating their region. The situation confronting Japan in Asia between 1900 and 1945 looked quite different: Russia was the only great power located on the Asian mainland, but it was usually more concerned with events in Europe than in Asia. Plus, it was a militarily weak great power for much of that period. Russia’s immediate neighbors were feeble states like Korea and China, which were inviting targets for Japanese aggression. In short, the Asian continent was open for penetration from abroad, which of course is why the European great powers had empires there. The European continent, on the other hand, was effectively a giant fortress closed to conquest by distant great powers like the United Kingdom and the United States.

Second, I argued earlier that great powers are not seriously committed to maintaining peace but instead aim to maximize their share of world power. On this point, it is worth noting that the United States was not willing at any point between 1900 and 1990 to take on a continental commitment for the purposes of keeping peace in Europe. No American troops were sent across the Atlantic to help prevent World War I or to stop the fighting after war broke out. Nor was the United States willing to accept a continental commitment to deter Nazi Germany or halt the fighting after Poland was attacked in September 1939. In both cases, the United States eventually joined the fight against Germany and helped win the war and create peace in Europe. But the United States did not fight to make peace in either world war. Instead, it fought to prevent a dangerous foe from achieving regional hegemony. Peace was a welcome byproduct of those endeavors. The same basic point holds for the Cold War: American military forces were in Europe to contain the Soviet Union, not to maintain peace. The long peace that ensued was the happy consequence of a successful deterrence policy.

We find a similiar story in Northeast Asia. The United States did not intervene with force to shut down the Russo-Japanese War (1904–5), nor did it send troops to Northeast Asia in the 1930s, when Japan took the offensive on the Asian mainland, conquering Manchuria and large portions of China in a series of brutal military campaigns. The United States began making serious moves to get militarily involved in Asia during the summer of 1941, not because American leaders were determined to bring peace to the region, but because they feared that Japan would join forces with Nazi Germany and decisively defeat the Red Army, making hegemons of Germany in Europe and Japan in Northeast Asia. The United States fought a war in the Far East between 1941 and 1945 to prevent that outcome. As in Europe, American troops were stationed in Northeast Asia during the Cold War to prevent the Soviet Union from dominating the region, not to keep peace.

I have emphasized that when offshore balancers like the United Kingdom and the United States confront a potential hegemon in Europe or Northeast Asia they prefer to buck-pass to other great powers rather than directly confront the threat themselves. Of course, this preference for buck-passing over balancing is common to all great powers, not just offshore balancers. Chapter 8 will consider how states choose between these two strategies.