But that's quite literally not what's happening. The problem is companies that do a significant portion of their business in one country using legal loopholes to claim that those operations actually occurred in other jurisdictions where they would have virtually zero tax liability.

Imagine you are a smaller country here. You probably don't want your tax law to be determined by third parties.

If anyone tried to enforce things like this on the US we'd be having a press conference with some general explaining that attacks on our sovereignty will have consequences.

Perhaps they're of the "tax is theft" branch of libertarianism

I think that's a pretty absurd argument. Like some sort of weird variation of fallacious slippery slope. So because someone is for international treaties on war crime he must be for global taxation rates? Would it be ridiculous to not just support a full on global government then since we already have bodies governing war crimes? That lazy line of thinking can be used for pretty much everything