There's also an absence of an apparent ulterior motive. The US and Japan were also on opposite sides of the world, and had little to no prior history. It's not clear why (or along what lines) they would cooperate with each other in the presence of such real territorial conflict.

Germany is a somewhat closer case. Germany and the US had a shared history and tradition. Socialist / Communist politics were widespread in both, and the US was largely divided as to whether they would support or oppose the German socialists / war. So there is a much stronger case for an ulterior motive here. Indeed, Germany indisputably wanted many of their own people to be killed. Their leadership's desire to kill jewish German is beyond dispute... so as it relates to other classes of Germans (e.g. those who fill the Wiermact ranks)... I don't think we can rule out the possibility on the grounds that those people were (also) German.

However, to get back to the territorial aspect, Germany conquered a lot of land, and the Allies took it back. So, a closer situation to the current stalemate in Ukraine would be WWI. If they're not making any progress in terms of territory... what progress do they think they're making? The main change I see from here is that people are dying... so that's probably the whole point.

It's hypocritical for Europe to claim North American territory, and then claim we should be concerned about a European nation claiming European territory.

Russia and Ukraine are both on the same continent. They're neighbors. That's a much tougher decision than whether a European nation should control Greenland... that's not even on the same hemisphere.