Actually the president should summon the soldier to the White House and PERSONALLY pin a purple heart on his chest for having been wounded in combat and then send him back to Iraq with direct orders to continue to find the terrorists and KILL THEM!
I can think of some past Presidents who would have done just that. He'd have to do it on national TV right in the Oval Office. It would put the Old Media and the soldier's chain of command on notice not to mess around with him and that the President has his back. There would be no need for an official pardon or anything - the message would be clear.