With all due respect, the US Gov doesn't have to depend on TI for defense/national security chips. They could cut a deal with Intel as soon as the ink is dry on the security clearances.
In principle, in case of extreme urgency on a level of national emergency, they can, but this will also mean that it will be Intel who will have to redesign, and adapt the mask. Some military IP is so old, that it isn't even digitised, or is a non-syntheszed, hand drawn IP. Some of it will likely be completely unworkable on a new CMOS process because of dependency on some, now exotic, high speed CML logic.
And we are only talking about digital chips. Analog chips case will likely be hopeless without a specialty analog foundry.
In the peacetime, it is very, very unlikely they will be able to "reorient" to make defence chips, as it will seriously disrupt the company.
And in the end, it may not matter at all if the supply chain for materials will go down in case of a military conflict.
