Elites physically and mentally fit but morally unfit ....
Morally, WWII was a truly sordid war where in all the world's nations (with just a few sturdy exceptions) only fought the Axis if the Axis attacked them first.
Certainly that was the case of the two biggest neutrals or non-interventionalists, the USSR and the USA ,but it applies to all but the British Commonwealth as well.
And even in the Commonwealth , in places like Eire, Quebec, Afrikaner South Africa, Congress India et al, hundreds of millions were unwilling to fight the Axis.