Some interesting opinion.
We have a professional, volunteer military, and this guy would know that he was likely to face action in theatres of war. He signed up to an organisation that functions with heirarchy and discipline, and his training would have reinforced that. Colleagues relied on him.
He claims to be disallusioned with the objectives of the war in Afghanistan - If he felt that strongly about it, why did he not register as a Conscientious Objector, rather than going AWOL?
At the Nuremburg War Crime Trials,One of the main defences expressed by German soldiers and officers quizzed about the various atrocities they committed was that " they were only following orders".
I dont want a bunch of unthinking robots in the army, blindly and unquestioningly following any order - but neither can the army be just a social club, whose membership you can abandon the moment you feel like it.
Of course he should face a Courts Martial for desertion - there can be no realistic question of that. What punishment he receives should be proportionate to the that crime. I would have had much more respect for him had he expressed his views whilst remaining in service, rather than just running away.