AFAIK DoD has always had contract with Intel, IBM, GF for certain things Fab within US. And they rarely ( If ever ) use anything that is leading edge anyway. Their requirement are critically different to mainstream consumer usage where reliability of node is paramount. Samsung is also building a Fab in Austin which has an upgrade path from IBM ( now GF ) node. I dont see what TSMC has to offer in both National Security and Fab Production Business prospective.

That is of course, as you said unless both Intel and Samsung seriously messed up their plan.