> Essentially its a very old (~2.5k year) idea that the interaction between an incumbent power and rising "challenger" power inevitably leads to war between the two.

It sounds plausible, but if it is this old there must be a long list of examples. What are some of them?

As LarsDu88 mentioned above, its actually not this old. The idea is recent but is based on an ancient conflict. That is my mistake. The wiki article has interesting info on the examples that the originator saw:

https://en.wikipedia.org/wiki/Thucydides_Trap

Thanks for the list of examples.

It is odd to see a single country being repeated at different times as the "incumbent" power.

The latest example in the list shows "UK and France" as incumbent power and Germany as rising for the 1990s - present.

The US is only listed for the 1940s - 1980s as incumbent, with Japan and Soviet Union as rising.