Drug prohibition?

Other than being in and of itself something worthwhile to think about, another reason that I wanted to post the above video is due to a great quote from Albert Einstein that it brought to my attention. Speaking of alcohol prohibition in the 1920s, he said:

... nothing is more destructive of respect for the government and the law of the land than passing laws which cannot be enforced.

I wonder if the same could be said about a lot of other legislative changes, leading either to crimes for which prosecution typically depends on the assumption that one of the parties involved is infallible.

Drug addictions like other addictions are harmful but is a war on drugs approach the solution? The video above notes that under this sort of program a tiny percentage of drug program funding goes to drug treatment programs while drugs have increased in purity while simultaneously decreasing in cost.