This is somewhat true, but to be fair there are only a few countries the US and it’s allies don’t do business with - as long as you don’t land in Iran or North Korea you’d be in pretty good shape.
Many of those countries are friendly (extremely so) to the US. For example, the US is perfectly happy to ship aircraft parts (and even fully functional military aircraft) to Afghani buyers; they just give non-binding advice to US citizens that traveling to a war zone is maaaaaybe not the safest idea.
