Gandhi defeat Hitler? Don't think so.
Referring to the part where Gandhi says that even Hitler can be defeated through civil disobedience, although through some suffering.
Well, the English considered themselves superior people who were meant to rule the world. The Nazis thought they were superior people who were meant to cleanse the world. Taking the non-violent path against Hitler would have only ended in defeat, after thousands were gassed in concentration camps.
It probably wouldn't have worked in India either, if the English weren't so terribly weakened in WW-II. Not saying that Gandhi wasn't a great man. He was.