I was stationed in Okinawa from 1969 - 1970, US Army. After Nixon was elected president, his "secret" plan was to get out and declare victory. Turn the war over the Vietnamese, end the draft, and cut the damn budget so he could pump money into domestic cash grants designed to let the mayors and legislatures buy peace in the burning riotous inner cities of America.
In the summer of 1970, the Army found out it couldn't meet its payroll. They had drafted over half a million men in 1969 and 70 and had that many in Vietnam. We had tens of thousands in Korea and Germany. Nixon and Kissinger had announced an "all volunteer" Army and started to raise pay and benefits. Standards were being raised as well. The rag-tag draftee had to go. RIF's or Reduction In Force pink slips went out to officers who weren't Regular Army and didn't make the right promotion lists. The Reserves and Guard forces were actually reducing in force. The 1963-1966 enlistees were finishing up their 6 year contracts and there were no more 2 year waiting lists to take their place.
The Military wanted the draftees out and they wanted to fill up the reserve ranks but with non-draftees. So a two prong strategy was devised. Drug test the troops.
Drug use was rampant in the service. All the pot and smack from SE Asia was cheap and abundant. Anyone flunking a test was given a choice of an instant general (not dishonorable) discharge and in exchange for not demanding VA medical benefits, the Army promised not to prosecute offenders. To get "good" people into the Reserves, enlistees (not draftees) that had been overseas at least 12 months and had over 1 year left on their enlistment, could finish their term of service with a Reserve or Guard unit near their homes. Bingo, got rid of draftee druggies and got some experienced "good" troops to replenish the reserves.
We had a lot of cross contamination, however, with draftee and enlistees flunking drug tests. Even officers had to take the test. They were surprise tests and would sweep up anyone in the area, officer or enlisted man. I would charge $5 cash for my excess urine for anyone that had the cash. My first customer was a lieutenant at my ammo dump. He smoked pot but still wanted to stay in the Army.
When I got to my reserve unit back home, they had tested me at separation and told us we were subject to random testing during our two week summer camp. The officers in our hospital unit were subject to drug testing during their annual fitness checkup. Similar to what pilots had to go through.
That's it! Bush skipped his flight physical in 1972 because he knew he'd flunk the drug test. He'd work all day chasing skirts and drinking beer knowing damn well he wasn't going to beat Senator Sparkman from Alabama. Then he'd go home and tote some dope with his buddies.
By the way, everyone I met in the reserves told me they joined, not to serve their country, but they knew that with the draft, no reserve or guard units would be called up and sent to Vietnam. Smart? Cowards? Just "getting over"? Bush didn't have to go. Kerry volunteered. Who's best suited with their military experience to be commander-in-chief?