Nazi Germany and Imperial Japan embarked on aggressive war plans on opposite sides of the globe at nearly the same time.
Was this a coincidence, or were there structural factors in the world system that made this happen?
The case for coincidence is obvious. It's strengthened by the fact that there have always been aggressive states, so finding two on different sides of the world is not hard (you can do it today). The fact that it was two industrialized powers is just coincidence.
Unfortunately, I only have a bachelor's in history so I can't even really speculate about the opposite case. I've heard a few lectures about structural realism in international relations, so I know there are these kinds of discussion in faculty lounges.
Coincidence or more to the story?