In neither world war, then, did the United States enter for considerations of the balance of power. In both, the entry of the United States so quickly and completely tilted the balance of power in favor of the side it joined, that had the United States been regarded as an element in the balance, the wars in the form they took would never have broken out. After World War I, the United States withdrew in disillusionment. After World War II that recourse was not open, although many in the Truman administration feared it and worked to prevent it. It took time before it became apparent, either to Americans or to any others, that the balance had been shifted permanently during, and to some extent as a result of, the war. It took time before it was realized that Britain would not recover, that France was not a world power, and that noncommunist China would not become the guardian of the Far East. Yet, paradoxically, while the postwar hope of a concert gave way, just as it did after the Congress of Vienna (1814–1815), to an ideological confrontation, the balance of power was being restored.
It has often been argued that the balance of power is really an imbalance of power. If the balance is to work at all, there must be at least three parties, such that any two can overpower the third, should its activities become too threatening. More than three is better; but three is the minimum. The idea of balance as implying some sort of equality gives way readily to the idea of balance as superiority of force on the side of the existing order. The balance between two powers or groups—sometimes called the "simple" balance—is altogether too unstable. It requires a degree of vigilance, of preparedness, of national concentration on defense, which is ultimately intolerable. The Cold War implied just such a balance, of course, and it should come as no surprise that the rhetoric of the Cold War, on both sides (although recent attention has been given to that of the West), did not speak of balance at all, but looked to victory. That is a characteristic of the simple balance.
