It would only come to nukes if the other side escalated to weaponry just below nukes. In that case, it's not "nuking Americans in Seattle", it's "nuking well organized terrorist cells using advanced weaponry, in order to save further loss of life."

The point is that no matter how much "power" the federal government has granted to civilians via the 2nd amendment, the federal government will ALWAYS have more.

Neither do I, but the US doesn’t currently have any serious independence movements and last time it did things went very badly indeed.

It would never be “over a sovereignty dispute”, it would be to stop what the rebels were imminently going to do in that sovereignty dispute. Nuking is extreme, but there will always be (at least, in the eyes of the government) a excuse to escalate to the level beyond what is available to the rebels to protect the innocent threatened by them.