Apple earned it offshore
Apple payed offshore taxes
Apple holds the cash offshore
I don't see the problem, Apple would be taxed double and i would be taxed again via the dividend, there are limits to taxing.
3 only happens because of 1 and 2. No one is proposing 2 still happens despite 3.
And it's not that simple. Most industrialized nations can probably agree on a reasonable minimum. Otherwise there will be corporations that keep profits offshore without being taxed illegally despite earning it in a country that would otherwise tax it.
The international tax doesn't care where you claimed you earned it. It only cares how much you were taxed where you earned it. So now they'd have to lie and say they were taxed more in territory A than they actually were. That would add another layer of complexity to tax dodging.
Do you know that Google only pays about a 2% tax rate? They sure as hell earn more here for 35% of their US earnings to only be 2% of their total earnings (assuming they're taxed 0% elsewhere). It's obvious companies are shifting profits. Make it harder and make them pay their due.