Yep military use of stimulants goes way back to at least WW2.
Before that you get into the period when most soldiers got roaring drunk before battle, to build up their courage.
Nothing new here.
Pretty ridiculous to be worried about altered consciousness in people whose job is to slaughter other people.
It's a job that's better suited for machines anyways. UCAV's are already here (Predator+Hellfire) and will probably become our main weapon in our lifetimes.
Until then:
Survival kit contents check. In them you'll find: one 45 caliber automatic, two boxes of ammunition, four days concentrated emergency rations, one drug issue containing antibiotics, morphine, vitamin pills, pep pills, sleeping pills, tranquilizer pills, one miniature combination Russian phrase book and Bible, one hundred dollars in rubles, one hundred in gold, nine packs of chewing gum, one issue of prophylactics, three lipsticks, three pairs of nylon stockings. Shoot! A fella could have a pretty good weekend in Vegas with all that stuff.
