Do other countries put US hardware and software companies on blacklists for their involvement with DoD? If so, then I think quite a few major US tech companies would be unable to do business outside the US and Europe.
For instance, I recently started investing in an excitingly expensive hobby, night vision. The tubes in those things are so heavily restricted that I cannot even let a foreign national touch them, technically. Which makes it interesting considering my girlfriend is a Tunisian foreign national here on a work visa, so technically I cannot show her my cool new toys I spent thousands of dollars on.
My partner would be happy if I could not tell her or show her the cool stuff I work on :P.
They can't ban the hardware, of course. While in the US finding a Chinese part in military hardware is a reason to stop the line, they rely extensively on US parts.