I’ve had this discussion many times with students who are active military: They were, across the board, horrified and disgusted by Trump’s desire to use troops against protesters - but also, and rightfully, quick to add that democracy is in great peril if it has to rely on soldiers defying orders.
Things have gone way off the rails if we’re relying on service members’ duty to refuse unlawful orders (assuming they’d still be considered unlawful, given the SCOTUS decision). And all it takes is one guy to decide to obey.
also the “don’t worry troops won’t follow orders” only works for so long until all the soldiers with a moral compass are arrested/discharged and the only ones left are the monsters and soulless drones. see: policing.