Normally I like to just read the forum but feel I must post a response to this thread.
I left the Air Force a few years back and at the time had no problem with the concept of CDT. I now work for a large company that also uses random screening; they also have a strict no alcohol policy (its less than the drink drive limit). I still have no problem with this as it sets a standard required by the individuals it employs and one from which I have nothing to hide.
I do however feel that the mentality displayed by some of the people still serving can be described as slightly out of touch. To make it clear, the use of soft drugs does not necessarily mean the individual is going to go on to harder drugs in the same sense that someone who likes a sociable drink will not become an alcoholic.
The rate at which the public attitude views the use of recreational drugs is rapidly changing and it is from these people that future recruits will come from, their attitude will be different and it is something the armed forces on a whole are going to have to accept. They will have to positively encourage and teach a sensible attitude of restraint to either substance. At present the scare stories promoted by the powers that be are in effect wrong. They are outdated concepts not to dissimilar to the ideas that were promoted by the American government a few administrations back.
I have worked with both the military and the police force and having grown up in an area which is considered rife with both drugs and crime have seen that the promotion of ill informed advice and a oppressive attitude does nothing to tackle the problem, more so to drive it underground and promote a climate of distrust.