The UN Charter is basically a statement of intents. It has no force of law, because its institutions, except for the security council have no ability to enforce it. They have put no obstacle in from of the US. So HOW does the Charter forbid it?
They have put no obstacle in from of the US. So HOW does the Charter forbid it? It doesn't have to.
It's just like the useless phrase "international law"
There is no such thing. If there were it would be a cruel joke: just imagine the millions killed in Africa in just the last 20 years.
But it makes the clueless feel good, and it imbues them with some mythical cloak of moral superiority.