re: #357 Feline Fearless Leader
Off the top of my head I would say only places in particularly nasty battles where troops on the field refused to carry out assaults guaranteed to generate heavy losses for no gains. Or they made a very tentative effort and immediately took cover.
American Civil War during Battle of Cold Harbor and some attacks during the Siege of Petersburg. And digging in books I could probably find an example or two from World War II on a much smaller scale (like company level) from the Italian Campaign.
In either case I don’t think this brought a large scale operation to a halt in the early stages - this was after things were underway. And not due to an order being “illegal”, but more due to it being obviously foolhardy or suicidal.
Might find small-unit refusals at the scenes of some massacres during the Indian Wars, and the helicopter crew that shut down Medina’s bullshit at Mai Lai. These are a long, long way from presidential orders because the DoD decision-making process is designed to short-circuit anything blatantly illegal.