We have had for decades any number of defense contractors in the U.S. not taken by force by the U.S. They seem to have, nonetheless, happily produced what the military was wanting to purchase.

I'm not sure what's different here.

The difference is that military procurement (a) isn't sold to the general public (try buying a machine gun) and (b) doesn't provide an opportunity to surveil and control the population (no citizens are also using F-35s to search how much Trump has made from crypto ventures).

AI is and does.

no US defense contractor can threaten the US government

which is why no US defense contractor is given unsupervised access to nukes, even when maintaining them