> Oh, I dont think its impossible for a supranational entity backed by national militaries to act as a policeman rather than a mafia don.
One person's policeman is another's mafia don. The international system as it exists, exists how you're describing it (supranational entity backed by national militaries) - it's just that the absence of the premier and effective military (America) makes that infeasible. So railing against America, calling the country a gang and mafia don, and advocating for it to withdraw from international organizations that it basically maintains flies in the face of your stated ideas and goals.
> An EU led super power emerging after an American collapse might successfully step into that role.
I mean that's certainly a scenario of events that could happen, but recent events on the ground suggest the EU is far too weak and neutered to supplant the United States in a meaningful way. It's more likely that the EU would break down and give way to war and conflict than create a unified state - hence the reason for NATO and the EU being created to babysit Europeans who continue to start war after war. More likely is just that the collapse of America (whatever that means) would give rise to either new nation state actors, or China, or some yet unknown and interesting new nation state.
One of the things that I think is interesting that has come out of the recent conflict in Ukraine that was started by Russia is that it is breaking the illusion of rules-based order on the international level and people are apparently very surprised about this.
Unfortunately might does make right at this level of interaction. To the extent that "fair" international organizations can exist they only can exist in that they are enforced by might and power. Actual bombs, guns, tanks, money, resources, and taking the lives of others. All of these organizations: the UN, ICC, WTO, you name it only exist in a meaningful way because they're literally backed by the United States' willingness to bomb or take away someone's toys (Russian yachts), and that you'd advocate for distancing the US from these organizations is to lead to the collapse of them without clear, ready replacements. No country or group of countries has the apparent ability to do this. Even the EU cannot conjure up a single, unified military and impose its will on the world.
Much of this anti-Americanism is geared toward sowing division where there is none and trying to convince Americans to be isolationist so that these international organizations do break down and then other countries can murder and pillage with impunity. I think it's safe to say we can reject this, in favor of a rules-based international order that is imperfect, but can be backed by America and supported by the EU and other participants such as Japan, Australia, Singapore, and others.
For the most part I just view this stuff (being anti-America, destroy international organizations, etc.) as right-wing talking points supported by bad actors to break ties in democracies.