I have a hard time believing that scenario. It would involve our military and state national guard units attacking citizens. I know about Waco and Ruby Ridge and Kent State. Would that be the same? If anything, it’d be like guerilla warfare but then the US military is better equipped to handle it than the average citizen and their personal guns.
CW2 would result in a good amount of that equipment disappearing. There would be divided loyalties within all branches of the armed forces.