You're basically saying the US should have let Iraq take Kuwait. Or let China take Taiwan?

Any weaker democratic country can be taken by a stronger non-democratic country?

"Invasion" is part of war. If you go to war against a country this may often involve invading. Wars are hard to win if you're not there. If there is no threat of going to war you are essentially yielding the world to Russia and China and the likes.

This is not to say the US hasn't made a lot of mistakes but I'll take a US world order with mistakes over a Chinese or Russian world order.