World War Two is what got us out of The Great Depression. (War is the most dynamic of socialist endeavors.) What made WWII so effective is that the government shoveled money at every business and entrepreneur that had an idea to help the war effort. The diversity of thought and creativity was unprecedented.
World War Three will not have the same effect. Government money will not be spread around like it was during WWII. Today, to fight war, money is only shoveled at the same few corporations who all have the very same perspective as to how to fight a war.