I agree about the punishing sanctions imposed on Germany after WW1 leading to the rise of Hitler.

You say that Hitler had to be stopped. Stopped from what exactly? His takeover of central Europe was rightly condemned, but posed no direct threat to Britain, France or the U.S. He also had designs on the USSR, which ultimately led to his attempted invasion of the latter country. But again, no direct threat to the 'Western' powers. Because the U.K. was predominantly 'Aryan', it was to be respected according to his perverse ideology and he did not go to war with it until the U.K. declared war first. (His overall intentions had been pretty clearly revealed in 'Mein Kampf'.)

The moral case for fighting Germany was based on his barbaric treatment of the Jewish and other minorities within Germany itself and in the countries his forces occupied. But might not Western countries have done more for those people by remaining neutral and accepting as many refugees as possible?