This biography should revive interest in one of the great (and misunderstood) theorists of international relations. Frei traces Morgenthau's life from his birth into a German-Jewish family to his burst into American fame in the late 1940s. His life was mostly hard and painful for many reasons: German antisemitism, an authoritarian and ungenerous father, a frequently unpleasant academic environment, and a long experience of exile and financial hardship. He survived thanks only to his defiant obstinacy and determination to produce great works. Frei shows how Morgenthau developed his philosophy in the 1920s and 1930s under the influence of Friedrich Nietzsche and other German thinkers. His resulting pessimism and realism about the human appetite for power and evil led to a profound culture shock when he arrived in the United States, with its "naive" political liberalism and optimistic faith in science. But Morgenthau's philosophy also had another, more neglected aspect: his attention to the moral obligations that he believed should guide politics. For Morgenthau, the reconciliation between realism without illusion and idealism aimed at the preservation of life and freedom was the task of statecraft. The wonderful book's only (but major) flaw is its lack of an index -- both surprising and disappointing coming from such a fine university press.