Subtitled ""American Diplomatic History, 1860-1900,"" this book covers three distinct periods in the development of U.S. foreign policy. The first period includes the delicate business of forestalling possible European intervention in our Civil War, the frustration of Louis Napoleon's plans to place the unhappy Maximilian on a throne in Mexico, and the purchase of Alaska from Russia. The second phase, a quarter of a century long, ""found interest in foreign affairs at the lowest ebb in all American history,"" while the last culminated in the imperialistic attitude which saw us forcing war upon Spain, intervening in international policy regarding Asia, and generally throwing our new-found weight around. Professor Dulles, a thorough-going observer of American political history, carefully follows the basic threads through these crucial years, and indicates how they structured ""the greatly expanded role America was to play in the global politics of the succeeding century."" Although both the subject and the approach to it are hardly new, by dint of steady attention to the main theme and great caution in drawing conclusions, he has managed to produce a worthwhile volume.