Hmm...so how does the chain of command work? If not the President, then the Sec of Def and/or the Chairman of the Joint Chiefs of Staff is a loose cannon with deployment orders? My understanding is that the President directs one or the other to issue those orders.
So you think Obama sits in his office every day and goes down a list and says, "OK, I think the 620th Medical Unit should go to Afghanistan starting....May 30th" or something like that? Or does he get into the nitty-gritty and say, "Issue orders for Smith, Jones, Lakin, Thomas, and Williams to deploy to Afghanistan." The order sending Lakin and his unit overseas did not originate with the White House. It didn't originate with the Secretary of Defense or the Secretary of the Army or even the Chief of Staff. It no doubt originated in whatever Army directorate is responsible for maintaining the rotation in and out of Iraq and Afghanistan. Obama may approve manning levels but the one who ordered Lakin to go is some General elsewhere in the Pentagon. It is his order, and his subordinate and that person's subordinate on down to his direct CO that Lakin is disobeying. And it is their order he will have to demonstrate is unlawful or their position he will have to prove is illegitimate. Not Obama's. Obama will never even enter into the picture.