In Defense of the National Interest: A Critical Examination of American Foreign Policy

Morgenthau argues that American foreign policy has been corrupted by a 'utopian' tendency to substitute universal moral principles for the concrete pursuit of national interest. He contends that the national interest, defined as power, must be the guiding standard. Crucially, he does not reject morality outright: he argues that a foreign policy derived from national interest is 'morally superior' to one inspired by universal moral principles, because it respects the moral duty of self-preservation and avoids the hubris that leads nations to impose their values on others .

Politics Among Nations (1948) is Morgenthau's systematic theoretical treatise on international politics. In Defense of the National Interest (1951) applies that realist framework specifically to American foreign policy, offering a sustained critique of what Morgenthau saw as the Wilsonian and legalistic habits of American statecraft . As a reviewer for Foreign Affairs put it, the book views American policy 'from the Realpolitik point of view' and is 'sharply critical' of the 'utopian bent' of American thinking .

Morgenthau's argument is that self-preservation is not merely a biological necessity but a moral duty, in the absence of an overriding moral obligation . A policy that acknowledges this duty is honest about its purposes. A policy that claims to act on universal moral principles, by contrast, is often a pretext for nationalistic universalism—imposing one nation's values on others. Morgenthau argues that such moral crusading is not only dangerous but hypocritical, since it masks particular interests behind claims of universal truth .

Morgenthau read the Federalist founders, particularly Alexander Hamilton and John Quincy Adams, for an explication of what he considered the authentic American tradition of national interest . He distilled three precepts from the founders' conception and nine rules governing the art of diplomacy . This move allowed him to argue that his realism was not foreign to American traditions but rather recovered a suppressed lineage of prudent statecraft that had been eclipsed by Wilsonian moralism.

The book was recognized as an important application of realist theory but drew significant criticism. Robert W. Tucker, reviewing in the American Political Science Review, argued that Morgenthau blurred the line between scientific analysis and political value judgments, and that his claim to derive moral conclusions from 'international political reality' was impossible . Edgar S. Furniss Jr., writing in The Journal of Politics, called it 'controversial' but praised its questions as 'of fundamental importance' . The core dispute was whether Morgenthau's realism was a neutral analytical framework or a disguised set of policy preferences.

The phrase captures Morgenthau's paradoxical position: the pursuit of national interest is not a concession to amoral power politics but a positive moral obligation. He argues that international politics would be more peaceful when all countries recognize 'the moral dignity of their national interest' . This means state leaders should prioritize national security—defined as the integrity of territory and institutions—and recognize that self-preservation is their most urgent moral concern. The phrase thus reframes realism as an ethic of responsibility rather than an abandonment of morality .