Between 1945 and 1950, relations between the United States and the Soviet Union underwent a 180-degree transformation. Erstwhile allies in the war against Germany and Japan, they became antagonists in a new global rivalry marked by the ominous expansion of Communist power and influence. While the Joint Chiefs of Staff repeatedly urged stronger military power to deal with this situation, their warnings had had limited effect on the Truman administration’s fiscal or defense policies. Exercising tight control over military spending, Truman preferred to address the Communist challenge with political, economic, and diplomatic initiatives. Bowing to these realities, the JCS fashioned a defense posture and war plans oriented toward a single contingency—an all-out global conflict. Maintenance of balanced conventional forces with flexible capabilities gave way to reliance on strategic bombardment with nuclear weapons as the country’s principal deterrent and first line of defense. Not everyone agreed that this was a sound course or that it adequately addressed the country’s increasingly diverse security needs. But at the time, reliance on strategic bombing with nuclear weapons was the country’s most practical, effective, and affordable form of defense