Reviews three periods of isolationist-internationalist debate over foreign policy, covering World Wars I and II and the threat of Soviet power following World War II. Points out the moralistic and humanitarian terms injected into reasons for action in each instance. Comments on shift of the debate in 1950's from Europe to Asia, Africa, and Latin America. Notes that economic stability in Europe permitted a change in focus of US foreign policy. Explains how the threat of communism in Asia prevents economic stability. Discusses the debate centered on the philosophies of "peace" and "force," notes limitations in each approach, and recommends use of force to attain rational political ends. [TAIC]