Earlier quoted context omitted.
It doesn't really matter because, as the dominant world power and arbiter of the world's currency, the US can invent legal grounds to do pretty much anything to anyone. The US government is so powerful, they are the only country that enforces a draconian global taxation scheme on any citizen or person who has ever held a US green card, even after they permanently leave the country. The US treasury will withhold the a…
USA can't tax non-citizens. Revoke citizenship if you really don't want to pay. That comes with a lot of downsides though (no more US passport, no getting rescued by the US if you wander into North Korea, etc), which implies the taxes aren't for nothing just because you live out-of-country.
The USA can, and does, tax non-citizens. Many countries tax non-citizens. Go out and buy a foreign stock-they will tax you on earnings or dividends. Go visit a country and pay the local sales tax.