Steven Walt and Will Inoden have an exchange at Foreign Policy magazine about the kind of "realism" reflected in Obama's Oslo speech. Walt argues that it departs significantly from the classical realist position of political scientists like Walt. Inoden notes that Walt has failed to distinguish between "realism" and "Christian realism":
But where Walt errs is in his conflation of "Christian realism" with "realism," and here his critique of Brooks, Packer, Sullivan et al for praising the Niebuhrian spirit in Obama's speech misses the mark. "Realism" seems to come in all manner of shapes, sizes, and flavors these days, and the point here is not to plumb those endless murky depths but rather to highlight the distinctives of Christian realism.
So while Walt's expertise on academic realism is formidable, the Christian realism developed most prominently by Reinhold Niebuhr is in important ways a different kettle of fish. If Obama's Oslo speech may not have been "realistic" in the conventional academic sense, its themes were largely consistent with the traditions of Christian realism.
Christian realism and academic realism do share much. Both consider power a first-order factor, both are anti-utopian, both caution about unanticipated outcomes of good intentions, both assume human folly and national self-interest, both hold that order precedes justice, and both take the salience of the nation-state as the basic unit in international relations. No surprise, then, that in his day Niebuhr frequently found common cause with more traditional realists such as George Kennan and Hans Morgenthau.
But there are significant differences as well. Christian Realism is primarily a philosophy about the individual human being and the meaning of history, rather than of how the international system works. It focuses on the limits of human aspirations and the pervasiveness of human pride, but also the fact of human dignity and the possibility of proximate justice here on earth, even if absolute justice is left for the end of history. Moreover, while Niebuhr harbored few delusions about the capabilities of the United Nations, he and his fellow Christian realists still placed greater faith in such international institutions -- even to the point of helping create the intellectual architecture for the United Nations -- than traditional realists.
Christian realism also gives more primacy to moral judgments, including about the internal nature of societies, than academic realism. Niebuhr broke from his fellow liberals in the 1930s by condemning Nazi Germany for its categorical evil and urging the United States to take up arms and defeat it. In the next decade he again condemned Soviet communism as evil and urged a robust military posture -- including nuclear arms -- to resist it. In neither case was it simply about one nation-state balancing the rise of another nation-state or protecting its own interests. His most pointed opposition to the USSR came not because it was a rival power but because of its existential threat and sacrilegious zeal. In Niebuhr's pointed words, "Hell knows no fury like that of a prophet of a secular religion, become the priest-king of a Utopian State." Likewise, Niebuhr's Christian realism sometimes led him to take positions that deviated from the traditional realists of the day -- such as his fervent and outspoken support for Israel during its precarious first decade of existence.