So well did Americans learn their lesson and follow Washington's injunction that during the Napoleonic Wars (1803–1815) Americans seemed to have little or no interest in the issues. Neutral rights, and no doubt a free hand in the Americas, were what concerned them. Neither the possibility that Napoleon might come to dominate the world, which loomed so large to many Britons, nor the possibility that he might overthrow the archaic monarchies of Europe and bring in a new order, which seemed to others an exciting prospect, affected Americans to any great extent.
By that time the doctrine of the balance of power had ceased to interest Americans, and so it remained for a full century. Most students would contend that a balance of power existed in the nineteenth century and perhaps worked more effectively than ever before or since, and that whether they chose to recognize the balance or not, Americans were beneficiaries of it. Americans then gave little weight to that proposition, and they were right. They quickly discovered a doctrine, or a practice, that served their needs better than any contribution to a balance of power. This was the American withdrawal from the affairs of Europe—in certain matters only—enshrined in the Monroe Doctrine of 1823. Attacking the international system, the British radical Richard Cobden could use as one of his chief arguments the fact that "America, with infinite wisdom, refuses to be a party to the 'balance of power'" (Cobden's emphasis).
If Americans could so largely ignore the existence of the balance on which their security finally rested, it follows that the balance was more stable than it has often been. This is, clearly, a balance in one sense, and perhaps in the most obvious sense—forces resting in equilibrium without perpetual adjustment and still more without fundamental readjustment. When the balance of power is most noticed, it is because it must be maintained—that is, because it is in perpetual danger of tipping too far to one side or the other. What, then, is the condition of stability such that it can even be neglected? American experience suggests that it is the introduction of what might be called an element of friction into the balance, something that operates on neither side, but inhibits movement or makes it more difficult.
It was this friction that the geographical distance of the United States from the power center of Europe introduced, so that for Americans the balance of power was always less delicate. Until the era of modern communications, this distance clearly made it more difficult for the United States to intervene in a European quarrel. Both more resources and more time were needed to sustain effective intervention. On the other hand, the converse was equally true. While it might be arguable that the complete overthrow of the European balance, and the dominance of Europe by one power or group of powers, would endanger the security of the United States, it was also arguable that that dominance would have to be more complete than it was ever likely in practice to be. The balance in Europe would have to be tipped far past the point at which the security of some European states was endangered before there could be any threat to the security of the United States. As Abraham Lincoln put it, rhetorically enough, in an address before the Young Men's Lyceum of Springfield, Illinois, on 27 January 1838: "All the armies of Europe, Asia and Africa combined, with all the treasure of the earth (our own excepted) in their military chest; with a Bonaparte for a commander, could not by force, take a drink from the Ohio, or make a track on the Blue Ridge, in a trial of a thousand years."
This meant that American reluctance to be drawn into the quarrels of Europe was for long a realistic one. Americans could benefit from the balance of power without being fully conscious of it. The European states made little effort to involve the United States in their concerns. The well-known claim made in 1826 by George Canning, then British foreign secretary, to have "called the New World into existence, to redress the balance of the Old," was confined in practice to denying France "Spain with the Indies." With that accomplished, there was an agreement (so general that it could be ignored) that there was no effective and inexpensive way of using American support in a European quarrel; nor, per contra, of using European support in an American quarrel. For most of the nineteenth century Britain was the only major power that had serious differences with the United States. Difficulties arose over Canada, over Britain's remaining Caribbean possessions, and over trade, but the British always concluded that such differences should be settled—if need be, even by British surrender—without attempting to involve other powers. They were not prepared to call in the Old World to redress the balance of the New.
Perhaps this became most obvious at times when it looked as if the United States might not continue to dominate North America. In 1842 and 1843 it was widely supposed that Britain would guarantee the independence of Texas in return for the abolition of slavery there—as a preliminary to attacking slavery in the United States. "The present attempt upon Texas is the beginning of her operations upon us," wrote Secretary of State AbelP. Upshur. It came to nothing. Still more obviously, during the Civil War the Confederacy hoped for European recognition and even intervention. The hope rested on several grounds, but clearly implicit was the belief that a restored American union could not be in the interest of Europe. Nor was it. But none of the European powers—among which Britain was the key—had sufficient interest in creating an American balance to justify the European risks that the effort would entail. The relative remoteness of America meant that the effort would have had to be greater than the rewards justified, and great enough to entail unacceptable risks nearer home. It remained possible, and it was easier and safer, to exclude the United States from a European balance than to draw the Americas into an enlarged world balance.
Social change in the nineteenth century, however, was to reveal certain limitations in the doctrine of the balance of power. Some advocates of the balance have defended it on the ground that it maintains peace, or, at all events, sets limits to wars—a proposition supported to some extent by the American revolutionary war. Others have contended, with Edmund Burke, that the balance "has been the original [origin] of innumerable and fruitless wars" and "ever has been, and it is to be feared always will continue a cause of infinite contention and bloodshed." To such critics the purpose, or at any rate the desirable result, of the balance was the maintenance not of peace but of liberty. As many have pointed out, there is something inconsistent about the notion of going to war to preserve peace. One must calculate that continuing peace will result in some undesirable consequence, before war is justified. Loss of freedom is the most persuasive such consequence.
The nineteenth century saw the growth of romantic nationalism and democracy, and with it the demand of peoples for some voice in policy. In some areas rulers could behave as before, but increasingly the aggrandizement of princes was felt to have natural limits and was overshadowed by other forms of state activity. Within Europe, transfers of territory were found to cause more trouble than they were worth unless they were accompanied by wholesale transfers of population, a resource more acceptable in the twentieth century than in the nineteenth. The great revolution in nineteenth-century Europe, the unification of Germany—the unification of Italy had no equal consequences—was tolerated partly because its effect on the balance of power was not immediately foreseen, and partly because it was held to be an expression of nationalism that could not justly be opposed, rather than mere Prussian aggrandizement—so that it would increase stability rather than lessen it. In a war of the ordinary sort, by contrast, there were natural limits to what the victor could gain, and the destruction of a rival nation lay outside them. As that was accepted, it became possible to argue that defense itself, the most traditional and urgent duty of the nation-state, might have unacceptable consequences for the quality of life within the state. There seemed better ways than conquest to increase wealth and power. With the modern revolution in technology, and with the ever-increasing role of government in the lives of citizens, discussions of the balance of power took on a new dimension.