No one ordered Lakin to Iran to fight the mullahs. His commanding officer or commanding general ordered him to a preexisting theater of combat. That theater of combat is controlled by a unified combatant commander. That combatant commander is authorized - by federal statute and DoD directives - to rotate troops into and out of the theater of combat.
This is why Barack Obama and his eligibility to hold his office is immaterial and irrelevant to the military court. As such, no discussion about Obama's will be entertained at trial, and no discovery will be granted about any aspect of Obama's presidency.
So could Stanley McChrystal have just sent the 60,000 troops he wanted without a presidential directive to increase the troop level? Why or why not?