[mtts]

Interestingly, this is what the EU is. After WW2 it was decided to set things up so that European countries no longer could wage war against each other. Hence starting out with coal and steel (no war without those).

In such a setup, lack of democratic oversight is not a bug but a feature. It prevents democratically elected but possibly not entirely stable governments from doing something stupid. The drawback, of course, is that it also prevents democratically elected and intensely well meaning governments from doing the right thing if the supranational entity does not wish to facilitate that right thing.

This setup works (after a fashion) for a group of small and fairly weak countries, but for a single large and powerful country like the US there simply isn’t a supranational entity powerful enough to reign it in.