I wonder what would happen if the world just decided to ignore us. Canada and Mexico and Denmark stop talking to us about anything. The G7 becomes the G6, and doesn't invite us. No one (except Putin and Kim) returns the Felon's calls (nor the Sec of State, nor anyone else). No one allows Air Force One to land in their countries.

Just a thought experiment. I know it would never happen.

I think it would send the Felon into a rage. He would probably ramp up his threats (which would fall on deaf ears in my scenario, which would make him even more angry). He'd probably slap more tariffs, which would elicit a response in-kind. Short of military invasion, there is very little else he could do. He could close our overseas military bases, but that would harm us as much (if not more) than them. Nations are already looking at alternatives to American military hardware (since the USA has become unreliable, and you need a reliable partner to sell you spare parts and updates to the hardware you buy), and at least some are considering cancelling orders (like for the F35), which would be devastating to the defense industry workforce (layoffs would ensue).