The thing is, it's like any situation in which you feel your life is threatened (and yes, they don't look very threatened, but I'm talking about the bodies chemical reaction, not the physical situation), your body gets flooded with testoserone and other stuff that turns you into DS.
I am concerned that the army are sending out a message that it's OK to enjoy it. Yes, they will enjoy it, it's a survival technique, Grandad told me some stories that sound terrible out of context, but when you place him in the trenches, seeing friends around him dying every day, thinking that at any single second in the 24 hours could be your last... The Lizard Brain takes over, and the power rush is... intoxicating.
America had a lot of problems after Vietnam with soldiers who had been so used to living right on the very edge of their nerves that 'normal' life seemed boring and complacent, so they sought out danger, some became criminals, others recluses, some just went mad. I don't like the idea of encouraging soldiers towards that kind of fate again.