Slightly tangetical, but I think the depression in Germany gave the conditions required for Hitler to rise to power, but a lot of what led to World War 2 was (a) unwillingness to accept the problem and (b) over-confidence on the part of several European countries. Hitler was in many ways the change from 'Old Tactics', where a mans' word was his bond and everything was done 'honourably' which were the standard rules of engagement in Europe to a more modern "If you're going to be a mug, I'm going to take advantage of it" mentality.
That's why I always think Chamberlain got a bad rap, it's kind of like complaining that Terrorists should be fighting in the open where we can see them.