Individualism and conformism, localism and centralization, pessimism and hope: these are some of the values and attitudes that have shaped American foreign policy in the 20th century, according to UCLA historian Dallek (Franklin D. Roosevelt and American Foreign Policy). Thus, from San Juan Hill to Vietnam, Dallek treats foreign policy as a reflection not of international politics but of the national mood. Necessarily, he generalizes: the Spanish-American War gave the US a foil, in the form of centralized, decadent Spain, to play off a self-image of individualism, small towns, and youth just when these things were passing away. Cold War anti-Communism gave Americans a different target: at a time when cultural conformism reigned, communism was a useful alien influence to hold the line against. In both periods, Dallek emphasizes the use of foreign policy as a unifying element in the face of domestic strife--whether resulting from economic conditions in the 1890s and 1930s, or from the ethnic and racial turmoil of the 1910s and 1960s. Some details, like the choice of locally-trained National Guard units to fight the war with Spain rather than a centrally-organized army, fit easily with Dab lek's scheme. Some, like the assertion that nostalgia dictated the turn away from Wilson's moralistic foreign policy to the isolationism of Harding, come close to being trite. Comparative references would have helped too: we are told that the Spanish were troubled by the undisciplined American fighting style personified by TR--but not that the Boers used similarly unorthodox methods at almost the same time. So much for the supposedly unique character of the Spanish-American War, on which a good deal of Dallek's interpretation depends. And his main point--that Americans have approached world affairs in terms of what they've chosen to see rather than what was there--is true of the foreign policy of any country. Still, Dallek's picture of an America-in-transformation--from nostalgia for a lost innocence to discomfort with Organization-Man efficiency--helps trace the main contours of American foreign policy without recourse to impersonal forces. Despite its weaknesses, an accomplished presentation of a provocative idea.