Some people in the American Government made millions off of WW2 while thousands of soldiers died. Australia warned us of an incoming Japanese fleet, but we took absolutely no action. The US government wanted to join the war, it's part of the military-industrial complex which state that companies (and the leaders of those companies) can actually make money off of war.
Before America was involved, we helped both sides... Did you know that the US Government actually sold jet fuel to the Nazis? Yeah, America made the bombing of London possible.
Thousands died while few cashed in. Maybe that's why some of the "hippies" didn't approve of it.