This is an interesting article on drug use during the Vietnam War. Looks like hippies and soldiers have a lot more in common than one might think. Makes me wonder where all the war money went:
HIGHER AND HIGHER:
DRUG USE AMONG U.S. FORCES IN VIETNAM
In 1898 the United States acquired control of the Philippines. The following year it began a brutal fight to suppress a guerrilla uprising. It is basic to guerrilla war that combatants will be mingled with the civilian population. Social behaviors flow one to the other. Soon after their arrival American soldiers learned to smoke opium. This practice became sufficiently common that U.S. Opium Commissioner Hamilton Wright felt compelled to deny it, claiming in a report to the 1909 Shanghai Opium Commission that “among the personnel of our Army and Navy [in the Philippines] there is not the slightest evidence that the use of opium or its derivatives has been introduced….”
In reality, the drug habit among U.S. military personnel was “alarmingly increasing,” so much so that its occurrence was an agenda item at the 1903 meeting of the American Pharmaceutical Association. There the Report of the Committee on Acquirement of Drug Habits noted that soldiers acquired the practice from Chinese and native Filipinos and that a number of enlisted men had been discharged for being habitual drug users. The discharge rate was several hundred percent higher during the previous five years than for any ten years before that.  The history of drug use among U.S. military personnel is not limited to the Philippines insurrection. The next time American soldiers fought to suppress guerrillas, in Vietnam, the use of drugs by American soldiers reached epidemic proportions.
Although marijuana is legally considered a drug according to the federal Controlled Substances Act, its use was treated differently from other drugs by American commanders and military lawyers in Vietnam.  This distinction will be maintained here; use of marijuana will be related separately from use of other drugs.
Marijuana was present in Vietnam before the arrival of the Americans. Drug laws were not well defined and their enforcement had little priority in the Vietnamese criminal justice system. There was no central Vietnamese drug enforcement agency and no government control over marijuana. A survey made in 1966 by the U.S. military command in the Saigon area showed there were 29 fixed outlets for the purchase of marijuana. 
A comparison has been made between Vietnamese use of marijuana and the manner in which the French treat wine and sex: there are cultural regulations for use, sale, and protocol but no inherent sense of “illicitness” as in the United States.  Journalist Richard Boyle mentions its use by South Vietnamese soldiers. He even relates an incident where he smoked marijuana with the South Vietnamese consul in Cambodia. Craven “A” and Park Lane were the popular brands of grass available in Saigon. It was sold in the form of pre-rolled cigarettes in genuine Craven “A” and Park Lane packages.
Former North Vietnamese Army (NVA) soldier Bao Ninh reports that smoking a marijuana-like substance became so pervasive that use spread throughout his entire regiment.  American soldiers note that the Vietnamese used marijuana openly. One saw it growing wild in Central Vietnam. Another discovered a sizeable quantity in the knapsack of a dead NVA soldier at Khe Sanh. 
Soldiers began using marijuana in Vietnam as early as 1963, during the advisory period, and before its use became widespread in the United States. Its popularity grew steadily.  In 1967 a Congressional investigation discovered 16 instances of marijuana use inside the Marine brig at Da Nang. The source was Vietnamese who gave it to prisoners on working parties, often throwing it into passing vehicles in which prisoners were riding.
Inmates not eligible for working parties did not necessarily have to go without marijuana. Marine lawyer Captain Robert W. Wachsmuth described how:
Members of working parties would obtain marijuana seeds [which were] planted in rows of dirt above the shower stalls which were opened to the outside by the gap between the tin roof and the wall….Spray from the prisoners’ showers would water the plants. When the plants reached a sufficient size, plastic…would be placed between the shower spray and the plant, causing the plant to die. The plants would then be crushed and rolled in toilet paper to make joints.
Other Marines found easy access from street vendors as their vehicles passed through urban areas.
For most of the Vietnam War, prosecution for even a slight trace of marijuana was a court-martial offense for Marines. The lack of a crime laboratory in Vietnam before 1968 was a major handicap to efforts to punish marijuana offenders. Drug samples were sent to Japan for testing, a process that took 45 days to complete. That same year marijuana detecting dogs were pressed into service to search for marijuana among Marines returning to Vietnam from R&R trips abroad. 
While the Marines were subjecting all marijuana offenders to courts-martial, the Army took only dealers and users of hard drugs to trial. The more severe Marine approach was a failure: in 1969, nearly half the cases tried by the Marine Corps in Vietnam involved marijuana possession. Marijuana use was no longer confined to rear area units. A drug rehabilitation center was established at Cua Viet for drug users from infantry battalions. A senior Marine legal officer admitted the helplessness in stemming the tide of marijuana use: “I don’t know what the solution is….I don’t know what the hell we are going to do.” 
Before 1968, marijuana use among soldiers was largely ignored by the Army. Newspaper stories describing its widespread use helped publicize this situation, inclining Army officials to label it as a problem. Their solution was a comprehensive program to eradicate its use. Armed Forces radio and television proclaimed the dangers of marijuana consumption. Drug education lectures became mandatory. Troop quarters and secluded fields were searched for marijuana. Soldiers were warned by chaplains, physicians, and legal officers that marijuana use could cause not only physiological damage and lead to psychosis, but also result in injury to men dependent on them. Arrests for marijuana possession reached as many as 1,000 in a single week.
Marijuana use was fairly easy to detect: it is a bulky commodity and emits a distinct odor when smoked. Consequently, the Army was able to wage a vigorous suppression campaign. In 1968, responding to U.S. pressure, the Vietnamese government publicly condemned the sale and use of marijuana. Province chiefs were ordered to forbid its cultivation. Aircraft were used to locate marijuana fields and South Vietnamese troops were sent into the field to destroy crops. U.S. Army Press releases claimed the drug problem was being brought under control. Eventually the anti-marijuana campaign by the Army was relaxed, although use remained high among enlisted personnel and junior officers. 
In fact, marijuana use was mostly a problem because it conflicted with American civilian and military values. Use of marijuana did not constitute an operational problem. Smoking in rear areas did not impact operations. Use among combat personnel came when units stood down rather when in the field. The Commanding General of the 3d Marine Division noted “there is no drug problem out in the hinterlands, because there was a self-policing by the troops themselves.” Life for combat soldiers depended on their being clear-headed. 
Army Major Joel Kaplan of the 98th Medical Detachment realistically appraised the use of marijuana. While noting that marijuana was used at high rates, alcohol consumption among career military personnel was a larger problem. “I think alcohol is a much more dangerous drug than marijuana.”  One Air Force officer understood well the difference: “When you get up there in those early hours, you want the klunk you’re flying with to be able to snap to. He’s a lot more likely to be fresh if he smoked grass the night before than if he was juiced.” A much larger problem was on the horizon for American military commanders in Vietnam. When heroin use became commonplace, one Army commanding officer rationally described the implications of marijuana use. “If it would get them to give up the hard stuff, I would buy all the marijuana and hashish in the Delta as a present.” 
Soldiers in Vietnam smoked marijuana and took other drugs who would not do so at home. A soldier’s friends become extremely important; new soldiers adhere to behavior of members of their group. Marine commander Major Ives W. Neely claimed “at least 70 to 80 percent” use within his company. Marines would catch a new man as he reported into the unit, instructing him that if he was going to buy marijuana he would buy it from them. If anyone told, turned in any of their names, “there were ways to do these people in…