— John Richardson – lawyer for "U.S. persons" abroad (@ExpatriationLaw) June 29, 2021
It is clear that the US extraterritorial tax regime, which imposes taxation on the non-US source income of US citizens living outside the United States, is an outrageous violation of the sovereignty of other nations. It is also an extreme injustice inflicted on US citizens living outside the United States. The US has successfully exported the extraterritorial tax regime to the world through a combination of (1) The US Internal Revenue Code (2) the FATCA IGAs (hunting down US citizens) and (3) the saving clause in US tax treaties (Country X agrees that the US can impose tax on any individual who has been identified as a US citizen and is tax resident of Country X). To understand the interplay between (1), (2) and (3) above see the following article I wrote for the American Expat Finance News Journal.