This was actually put into practice during the Spanish transition to democracy. The King gave a televised address denouncing an attempted fascist coup and ordered them to stand down: https://en.wikipedia.org/wiki/1981_Spanish_coup_attempt#Juan...

To this day, bullet holes remain in the ceiling of the Spanish parliament building to remind them of the coup attempt. I can't find it anymore, but there was a good drama movie about these events on Netflix a while ago.