Ukraine will very slowly lose its war against Russia, and Israel will very slowly lose its war against all of its neighbors. NATO and the US will turn on Israel at the absolute last second so they can pretend they're on the right side of history, which will convince nobody, but all state governments will play along because it's just easier that way. A bunch of seemingly unrelated countries in South America and Africa will adopt anti-US foreign policies, publicly using rhetoric about the US-backed genocide against the Palestinian people, but practically because the US was revealed to be a paper tiger. China will get 90% of the rebuilding contracts and experience a post-war economic boom, but it won't be as notable as the US's WW2 boom because China's economy is already so large and rapidly growing. The US will continue to think of itself as a great world power despite no longer being one, like Britain.

It's possible another US-backed front opens up, but I actually don't think that's so likely, as a Harris admin would be a continuation of the Biden admin, which is presumably already getting all the wars their backers want, or a Trump admin would fail to put together a war again. If the US does start another war, it'll be even more secondary than Ukraine/Russia, and accelerate the same conclusions as before. Unless the US actually starts a war over Taiwan, which I think is very unlikely because literally nobody benefits, but wars like that have happened before, and if it does then the results will probably be the same as outlined above but faster, but the chances of that going nuclear are high enough that I'm moving to a cave in the mountains if it happens.

All of this will of course be a stream of horrors for anyone anywhere near the fighting.