Appeasement. Chamberlain sat at a table with Hitler in 1938 signing a treaty and proclaiming "peace for our time". Shortly after, World War II began. Killing innocent people does not solve the problem, but sitting at a table with your enemy and proclaiming peace (when he just wants to kill more) does no good either.
The Greatest Generation? (preventing some thread hijack) While I don't doubt the bravery of those that defeated Hitler, I wonder if it's a little presumptious of any generation to consider themselves "the greatest"