http://www.bloomberg.com/news/2011-10-10/keynes-and-hayek-s-great-debate-part-3-commentary-by-nicholas-wapshott.htmlBy the early 1940s, the Keynesian Revolution in America was in full swing. Fast-moving events in Germany obliged Franklin D. Roosevelt to spend on the vast scale that John Maynard Keynes prescribed. Despite the president’s assurances during the 1940 presidential campaign -- “I have said this before, but I shall say it again and again and again: Your boys are not going to be sent into foreign wars” -- he ordered a gargantuan rearmament program. In 1940, the annual defense expenditure was $2.2 billion; the following year it reached a sizzling $13.7 billion.
“If expenditure on armaments really does cure unemployment, a grand experiment has begun,” Keynes declared in 1939. “We may learn a trick or two which will come in useful when the day of peace comes.”
The multiplier effect of so much public money being pumped into the American economy caused gross domestic product to jump by about $25 billion, with arms and other defense spending accounting for 46 percent of the increase. Even so, employment wasn’t restored to the pre-Roosevelt recession level until 1941, the year America was attacked by the Japanese at Pearl Harbor. “We saw the war as a justification of the Keynesian theory, the Keynesian doctrine, and the Keynesian recommendation,” John Kenneth Galbraith recalled.