Economic Production vs. Warfare
It is occasionally asserted that World War II got the U.S. out of the Great Depression. Measured GDP went up dramatically and unemployment dropped. However, what does that even mean? Unemployment dropped because of the draft. The unemployed were forced into uniform and shipped into miserable deadly conditions on the other side of the globe. Production consisted entirely of engines of destruction that brought only death and no joy. Whether or not the sacrifice was worth it or not, it did not "improve the economy". Economic action involves satisfying the wants of economic actors using scarce resources. Warfare involves killing your enemy. They can not be compared.