[OneEyedRobot]

>Were the great dictators just irrational?

Probably not at all, although it's hard to think/talk in a general fashion about such large systems.

The Axis Powers strike me as fighting a more reasonable war than (for instance) their WWI aggressor predecessors if you view it as simply a grab for land and resources. It's a thing that a Khanate or a Roman governor would understand and appreciate. I'd say that the actions of the Germans and Japanese would make perfect sense to the ruling class of most pre-modern states.

It's hard work to avoid Historian's Fallacy.