The use of meth in combat may play a role in Norjak, not only to keep the pilots awake, but to keep Danny sharp, as SOG troopers and others may have had it to enhance their capacities for surviving in the boonies. Here is my distillation from the sources I read, via EVick (Thanks, E!)
From Foundation for a Drug-Free World and “meth-kills”.org:
Amphetamine was first made in 1887 in Germany and methamphetamine, more potent and easy to make, was developed in Japan in 1919. The crystalline powder was soluble in water, making it a perfect candidate for injection.
Methamphetamine went into wide use during World War II, when both sides used it to keep troops awake. High doses were given to Japanese Kamikaze pilots before their suicide missions. After World War II, intravenous meth abuse in Japan reached epidemic proportions due to the fact that the Japanese military had large amounts of meth stockpiled, and had made it available to the public.
The United States military has used amphetamine in every war since World War II. In the Vietnam War, American soldiers used more amphetamine than the rest of the world did during World War II.