Walter Russell Mead has a powerful piece in the July/August issue of The National Interest. Entitled Goo-Goo Genocidaires, the piece argues that some of the worst genocides and mass slaughters of the past century (World War II and the holocaust, the Japanese rape of China, 50 years of Soviet repression, etc) were actively aided and abetted by well-meaning but deluded people who thought that appeasement would work -- that, for example, Hitler really wasn't all that bad and would no doubt be satisfied with just taking Austria.
He writes this in the context of today's Iran, and the world's (especially the UN's) reluctance to do anything really effective to stop Iran's nuclear program. The repeated sanctions that have been applied are essentially no more than slaps on the wrist with a wet noodle. And the question he asks is pertinent: will a nuclear-armed mullocracy in Iran be any easier to deal with, any less bellicose, any less ambitious to destroy Israel, any more helpful in stabilizing Afghanistan, any less willing to arm and fund terrorists? It's the right question to ask.