I like the parallel between WW1 and the Pelopponesian wars. Sparta and Athens exhausted each other in what was basically a Greek Civil War, similar to how Germany, Great Britain and France were decimated by WW1. This allowed an external, but culturally greek Macedon to rise to hegemony... America after WW1.

Of course further parallels start to break down afterwards... post WW2 would be the Hellenistic world, dominated by Macedonian successor states for a couple of centuries until the rise of Rome. I don't see an easy parallel.

I suppose a breakup of Nato or an US Civil war could conceivably lead to the rise of a new power eventually... maybe in South America... but no clear contenders right now.