It actually has to do with genetics.
You see, after WW2, the only europeans left alive were the pansies (the ones who didn't go to the war). So all the pansies bred pansie children. Hence why the Europeans are afraid to go to war now.
It's sort of like Squirrels. You have the squirrels that know how to avoid cars. And you have the squirrels that aren't smart enough to avoid the cars (not saying europeans aren't smart). Everyonce in a while one of the stupider squirrels will get a girl just by dumb luck.
Then comes along a bunch of hunters who take out the squirrels who avoid cars. The girl squirrels only have the the ones who will run in front of cars to breed with.
(Yet again, not saying that Europeans are stupid).