The US has tax agreements with lots of countries that prevent you from being taxed twice on the same income (and for other countries there are still solutions).

The US has tax agreements with lots of countries that prevent you from being taxed twice on the same income (and for other countries there are still solutions). Plus, you'd only be paying federal-level taxes, since you'd not be a resident of any state. Not sure about social security. Still, it is of course painful. As someone in the reverse situation (foreigner in the US), I had to pay income tax to Norway for the first three years after moving, with US taxes paid being deducted from what I owed. On the other hand, I did not need to pay the Norwegian equivalent of social security; income tax only. (Of course, the Norwegian tax system is also 100% digital, with very simple forms that are already filled out for you based on what your employer etc. have already reported to the authorities; the US stuff was just a small additional form. So in reality the painful part was and is the US tax return, which is ridiculously antiquated and complicated and involve lots of paperwork, especially when you have foreign bank accounts.)