As far as I'm concerned, it's up to them to defend themselves. At 600K dead fighting their wars for them, I think we've given quite enough young men defending the people of Europe and Asia. These are ancient civilizations quite capable of thinking for themselves. It's time they grew up and reacquainted themselves with the notion of military self-sufficiency.
That's exactly what we said before the Maginot Lines of France and before the rise of the Nazi party. Let the Eurpeans die. We thought we were immune until Pearl Harbor.
Isolationism didn't work for us then, and it will not work for us now.