O Canada?
I was struck by one of your many certitudes:
Nuclear weapons make it unlikely that the major nations of the world will ever be invaded by a neighboring superpower.
You know that Canada doesn't possess nuclear weapons, right? Based on a quick wikidive, it looks like there's never been an anti-WMD treaty Canada hasn't been eager to sign, going back to the 1930 Geneva Protocols. Good on them.
There's more than one kind of power in the world, and the US used to posses both hard and soft power. We once wielded a carrot alongside the stick. And Canada's a fine example of a country that's gone far based mostly on being the world's Mr. Nice Guy. The carrot works pretty well alone.
But repudiating the carrot as fit only for rabbits, and relying solely on the testosterone squirt of the big stick is the key indicator that a society has begun an irrevocable decline. We've thoughtlessly discarded the leadership you can only gain through soft power.
Because of Trump, the 21st century will belong to China and Russia. And everybody's good friend Canada.