But they would undoubtedly bring in foreign troops, who would be armed.
A few Americans would see such an event as a reason to get involved in the political process by writing their local newspapers, voting, and putting bumper stickers on their cars.
Most Americans, however, would see a target rich environment.
Never happen. The US military rank and file wouldn't allow it. Target rich environment would be an understatement. Politicos who went along with such a scheme would be dead men walking. The patriotic element of American citizenry would be overnight guerrillas. After the initial "shock" that our benevolent leaders would dare such a thing, I believe it would become a world-shaking revolutionary epoch.