The story of amphetamines since their discovery to their current enormously popular use - including in the military. From Life in the Fast Lane, in Chronicle of Higher Ed.:
The war bolstered the confluence of medical and commercial interests that made amphetamine the first antidepressant. The British and American forces adopted speed because it made soldiers more confident, despite authorities' knowing that by 1941 the German military had sharply curtailed its use of methamphetamine (a slight variant of the drug) because of its addictive qualities. The Allies administered the drug as a morale booster, notwithstanding a charade that the drug counteracted fatigue better than caffeine (two years of testing actually found amphetamine no more effective).
The drug helped win bloody, pivotal battles such as El Alamein and Tarawa. But the military's embrace of speed had serious side effects. An entire generation of young men had been turned on to the new pharmaceutical. There is evidence that the sanctioned use of amphetamines promoted drug abuse not only in the service but presumably after the war, too. That pattern repeated itself during the Vietnam War, when the military again distributed enormous quantities of amphetamine to American troops.
Speed is powerful stuff. Read the whole thing.