If invasion were threatened by a more powerful opponent, I see no reason why it would not use them. A better statement is that no government would be silly enough to invade a country that has nuclear weapons. History is on my side. The United States deals diplomatically with any country that has nuclear weapons.
Okay - say that Montana (just for example) were trying to seceed, and somehow got control of a dozen nuclear-tipped ICBM missles. The Federal gov’t is being adamant, threatening their border with lots of infantry. Where would you think they should target the ICBMs? What could they fire at without damaging noncombatants - noncombatants who may have been sympathetic until they were fired upon?
It’d be theoretically possible for the use of nukes to be strategically or tactically useful, if the divide were between two groups of states, geographically contiguous. But for a single state, I maintain that they’d be fools to even threaten with nukes. If they did, the likely response would be to see their missle silos targeted on a pre-emptive basis.
Danno
It’s the threat of their use and not their actual use which would make the federal government more timid to use massive armies. But that wouldn’t exclude the possibility of using specOps to kill off the leadership that was rebelling.
Well of course innocents would be threatened! The current threat of use of nuclear weapons by countries that have them is not a threat to the military! The state that seceded would target large population centers, most likely. Places like LA, NY, Houston, Washington DC, etc.
As to targeting the missile silos, they would probably just move the missiles to somewhere else.
For it to get to a point for a whole state to secede, most of the population of the state would probably have to be behind the movement. They would probably be on high alert, and I really doubt a special ops could get in. And even if they did, I doubt it would stop the secession at that point.