Why do rich people finance both sides of a war?

Les explains that wars are often manipulated by the super rich, not solely by patriotism. He notes that wealthy people will finance both sides of a war because they profit from war materiel regardless of who wins. They don't care about human misery; all they care about is how much they can get for machine guns, jets, and tanks. He observes that defense production is the backbone of many economies, including America's, and cites Czechoslovakia being told to stop war production but answering, "We can't. It's the backbone of our economy." Les clarifies he is not against defense spending but is realistically describing how war is manipulated for profit.