The EU isn't about international rules - members of the EU don't care at all about international rules. It's simply a covenant between countries that can be willingly entered and left.

The "rules based international order", on the other hand, is not voluntary. If the US decides that you are in breach, then it will be rectified with hard power. It's simply an abstraction for hegemony, and you don't get a choice to parcipate or not, the choice is made for you by the hegemon (which also happens to be its enforcer).