Unless he has the right people installed to confirm his order, or uses conventional weapons to goat the other guy into shooting first. North Korea would come to mind. Or a Chinese missile boat.....
No one in the U.S. Government is that stupid, given the situation that we have with Trump at the moment. Trust me, these people know the difference between right and wrong....and Trump's current mental state.
Three days ago I would have trusted law enforcement in DC to fend of a terrorist attack on the Capitol, alas, we have seen them waving those folks in and take selfies with them.
Quite right, really the rest of the world and I expect much of the US, won't be easily convinced by breezy assurances after these events, which are shaping up to be much more serious than just a mob incited by a sitting president - which is enough in itself to warrant huge concern about the security of major US institutions including the POTUS as C in C.
And there is a precedent, you won't be surprised from the last GOP crook as President, Nixon.
As the Watergate investigation closed in on the White House, Kissinger and the Secretary Of Defense apparently took steps to ensure any military order relayed by Nixon went through them first, Unconstitutional? Maybe, however Kissinger had a right to be worried when he got calls from Nixon, depressed, drunk, the usual self pity and lashing out at imagined opponents but it was the 'we gotta nuke 'em Henry' that was the worry.
And he has still not been arrested for sedition, this is what the rest of the world really do not get.