So did they stop any Iranian companies doing business with Iran? Did they stop China or Russia doing business with Iran? If Google Deepmind has to stop doing business with non-US citizens what will they do with their R & D in the UK and other countries? Will Mistral stop doing business in France? Will the Chinese AI companies stop doing business with everyone else (including China?) to retain access to US markets and banking?

The likely end result of this is that it will shrink the market to which American companies have access by more than it will shrink the market for anyone else.