To a large extent , what was called “the utopian-realist controversy”——one of the great debates of international-relations theory——focused on the extent to which political behavior and the anarchical circumstances of international politics could be transformed to a conditions of world order,based on cooperative normative standards and global interdependence. Emphasizing how international relationships ought to be conducted , the utopians despised balance-of-power politics, national armaments, the use of force in international affairs, and the secret treaties of alliance that preceded World War Ⅰ.Instead, they attached very great importance to international legal rights and obligations, a natural harmony of interest in peace as a regulator for preservation of international peace, a heavy reliance on reason in human affairs, and confidence in the peace-building function of world public opinion. Realists, on the contrary, stressed power and interest rather than ideals in international relations. Realism is basically conservative,empirical,suspicious of idealistic principles,and respectful of the lessons of history.
Nevertheless,Carr,a pragmatist ,took utopians and realists to task. He suggested that whereas the utopians ignore the lessons of history, the realists often read history too pessimistically. Whereas the idealist exaggerates freedom of choice, the realist exaggerates fixed casualty and slips into determinism. While the idealist may confuse national self-interest with universal moral principles, the realist runs the risk of cynicism and fails to provide any ground for purposive and meaningful action. He concludes that sound political theories contains elements of utopianism and realism , of power and of moral values.