Niebuhr's great foe was idealism. American idealism, he believed, comes in two forms: the idealism of the antiwar noninterventionists, who are embarrassed by power, and the idealism of pro-war imperialists, who disguise power as virtue. He said the non-interventionists, without mentioning Harry Emerson Fosdick by name, seek to preserve the purity of their souls, either by denouncing military actions or by demanding that every action taken be unequivocally virtuous. They exaggerate the sins committed by their own country, excuse the malevolence of its enemies, and, as later polemicists have put it, inevitably blame America first. This is all just a pious way of refusing to face real problems, Niebuhr argued.