问答题Practice 2　　Until early in this century, the isolationist tendency prevailed in American foreign policy. Then two factors projected America into world affairs: its rapidly expanding power, and the gradual collapse of the international system centered o

Practice 2　　Until early in this century, the isolationist tendency prevailed in American foreign policy. Then two factors projected America into world affairs: its rapidly expanding power, and the gradual collapse of the international system centered on Europe, the watershed presidencies marked this progression: Theodore Roosevelt’s and Woodrow Wilson’s. These men held the reins of government when world affairs were drawing a reluctant nation into their vortex. Both recognized that America had a crucial role to play in world affairs though they justified its emergence from isolation with opposite philosophies.　　Roosevelt was a sophisticated analyst of the balance of power. He insisted on an international role for America because its national interest demanded it, and because a global balance of power was inconceivable to him without American participation. For Wilson, the justification of America’s international role was messianic: America had an obligation, not to the balance of power, but to spread its principles throughout the world. During the Wilson’s Administration, America emerged as a key player in world affairs, proclaiming principles which, while reflecting the truisms of American though, nevertheless marked a revolutionary departure for Old World diplomats. These principles held that peace depends on the spread of democracy, that states should be judged by the same ethical criteria as individuals, and that the national interest consists of adhering to a universal system of law.