We're good here I think. They've been telling us that for decades over one thing or another all the time. They full well know that would be the call that would wipe themselves out. Logistics nightmare getting that many firearms gathered. You'd have to all at once, seriously. It could physically never happen without return fire...period.The largest and most heavily small arms armed army on the surface of the earth literally is US! You'd have to use an army of very sizable numbers to have enough influence of fear of force to do that and it would be hard to slip them in here.
PLUS we're eyeballs deep in 30yrs of accumulated veterans (also VERY armed) that don't just understand urban combat...they fucking invented it! They know it's a huge hornet's nest, to say the least! THEN there is the problem of using your own forces that will rebel rather than turn on their own nation. Loads would go along & willingly mole in, and sabotage from inside too!
This would eternally fail I believe.