1938 Again?

In the New York Times there was an op-ed piece that discussed the similarities between 1938 and today by Paul Krugman. The point of the article is that we are repeating the mistake that FDR made in 1938 where worries about the deficit overrode the need for more stimulus leading to a revived recession. He goes on to state that the beginning of World War II led to massive deficit spending that led to prosperity and the boom years that followed the war.

Of course one thing that we know about that period is that in addition to the massive deficit spending, much of the world infrastructure was destroyed in other parts of the world, giving this country with it great industrial base a significant advantage in selling products. In addition, the deficit spending was accompanied by rationing that led to a great pent up demand for consumer products following the end of hostilities. Another factor that can't be ignored, or at least shouldn't be ignored is that the war reduced the labor force in a number of ways. The most obvious would be the casualties but just as significant was the GI Bill that sent so many returning GIs back to school to receive training that they otherwise would not have had. Also, the threat of communism led to an expansion in the size of our military posture and spending that ebbed and flowed but consistently exceeded depression era levels.

One other factor in the post war years that shouldn't be ignored is the baby boom. This led to a tremendous increase in demand for housing and services in the newly created suburbs that exemplified the prosperity of the 50s and 60s.

Which one of these factors led to the prosperity we experienced post War? I would have trouble picking only one. So if we want to bring about a new prosperity I guess we have to spend trillions building up the army, diverting industry to war production, destroying much of the world's infrastructure and have another baby boom.