I seriously doubt he will be executed.
Military courts-martials are surprisingly leniant. And no matter what the sentence is, for every 1 day of good behavior, you get 2 days off of your sentence. I had a couple of guys in my artillery unti that went to army correctional facilities for some pretty bad shit, and they were out of jail before my enlistment was up.

But his new military occupational specialty will definately be: Mineral Decomposition Specialist... busting rocks in other words

There probably is a few thousand muslims in the US military.

Most stats I've read say that there are about 3 million muslims in the general US population (or about 1% of the US population is muslim), and there are about 1.4 million people in the US military, so assuming muslims make up 1% of the US military that would be 14,000 muslims in the military.

I don't know the actual stats but I spent 12 years in the Army '80-'92 and I personally do not recall a single muslim, but then again I did not make it a habit to inquire about a persons religion. I have serious doubts that there is anywhere near 14,000 muslims in the military.

Had a muslim in my atrilley unit.
Had two of them in my air traffic control unit.

In my opinion, they were great guys. Not like the extremist/terrorist types that make the news all the time these days.