~1920 is the peak of the British Empire in term of territory, anyways, the details are meaningless, what matters is that things move fast and just because you're at the top of your game right now doesn't mean you'll be in the same position in 100 years

I could also take the example of world wars, in France ww1 was deemed "la der des ders", which meant "the very last war" or "the war to end all wars", well 20 years later we were at it again

Or simply look at China, you don't even have to go back 100 years in the past to see drastic changes.

That's only the case if you include Canada and Australia, which were functionally independent at that point.

I'm not claiming nobody will invade France or Taiwan in the next 100 years, I'm claiming that the US is special. We haven't been invaded since 1812 and haven't really been attacked since 1941. It's reasonable to predict we won't be invaded or go to war with our neighbors for 100 years since it hasn't happened for 213 years