Comment by roenxi

> ...was WWII about "tribalism" and both sides being prone to violence, or was it about unjustified aggressors and justified responses?

All of the above. One of the major powers on the winning side was the British Empire, which existed because of a global campaign of unprovoked invasions that was pretty much unprecedented. And there was Stalin, who may escape the "tribalism" label on the basis that his campaigns of political murder were so wild it is difficult to discern patterns.

If we assume for the sake of tradition and argument that the responses were justified it might have been one of the few times in a century that the British were involved in a justified response. A momentous conflict indeed! It must have been unsettling for them. And, in all seriousness, they weren't involved because it was justified. They were acting amorally and it is a coincidence they were on the justified side that time.