Nor will a long prison sentence. 5 years captive by the Taliban makes 20 years in a military prison look like a cake walk.
Nothing can undo the damage done to those that searched for him...and those that laid their life on the line to do it are true heros. But punishing the man further won't change anything, nor dissuade anyone from doing it again when they have similar mental issues. Nor will this verdict dissuade the heros of the future from risking all to rescue them.
Justice is pointless without mercy. We cannot become so cold that evil wins another gain on our humanity and makes us one step closer to the ideals of those we fight.