In an introduction to Louis J. Halle's Civilization and Foreign Policy, Dean Acheson notes with approval that Halle believed a group of men, formerly members of the Policy Planning Staff of the United States State Department, to be seeking a new theory of foreign policy which would lie outside the traditional theory. Halle's work, like that of the others whose names were mentioned (George F. Kennan, Paul Nitze, and C. B. Marshall), represented a serious and searching analysis of the conceptual frame of American foreign policy, a search largely accompanied by a demand for a more realistic consideration of problems of power. The members of the Policy Planning Staff were by no means the only, or even the first, Americans to question American thinking on foreign policy from the standpoint of power politics. Without going back to Alexander Hamilton, we must consider, in particular, Hans J. Morgenthau and Reinhold Niebuhr. This kind of thinking is still being advanced; and, more recently, the warning that Americans misunderstood the problem of power was put with some forcefulness by Robert Endicott Osgood : “More than any other great nation, America's basic predispositions and her experience in world politics encourage the dissociation of power and policy.” There is no doubt that work of recent years has shown the increased seriousness of American interest in the problems of foreign policy and civilization. The contribution which these and other writers have made is a very great one. Despite many differences among themselves, their trend seems to embody a certain oneness, which lies in a perception of the problems of power. Acheson points to the practical experience of the State Department group and their intention to “see life steadily and see it whole,” in Matthew Arnold's famous phrase. Yet, a few years after these writers, whom Acheson so highly regarded, had tried to acquaint the American people with the realities of power in foreign policy, one of them, George F. Kennan, was publicly criticized by Acheson himself for “never having understood the realities of power politics.” Shortly thereafter, Acheson, in his latest book, reiterated the charge that “power politics” was, for Americans, still a derogatory term. Kennan, one of our most thoughtful and sensitive writers on foreign policy, and Acheson, one of our most articulate and eloquent secretaries of state, had failed to satisfy the American people, and Kennan had failed, apparently, to satisfy Acheson regarding the significance and the reality of power politics. Yet in the light of some of the literature which has appeared since the rise of these writers, whom we may call “realists” though they do not necessarily so characterize themselves, one may question whether the danger is still that which Acheson described. One who reads Henry A. Kissinger's Nuclear Weapons and Foreign Policy may wonder not whether Americans understand the realities of power but whether, indeed, some of them understand anything else. We face the danger that the wheel may come full circle, that a naïve idealism may be replaced by a purely methodical realism, and that the very words “politics” and “strategy” may become interchangeable terms. We face that danger, but let no one suspect that Americans, in general, have succumbed to it.