My favorite DVD set is by Ken Burns called Prohibition. This is well done and well researched and its very lessons are lost to the world. All of the forces that were at play in that led to and maintained prohibition are at play in the war of drugs.
The problem is that there are too many vested interests in the war on drugs to let it go away. The same now is then is that lives are destroyed in the process. Millions of dollars are made by all parties and these come down to cops on the beat, prison guards, lawyers and the bottom feeders that live off those engaged in those engaged in the front line of the war on drugs. These are bankers, mortgage holders, service industries and etc.
These bottom feeders reach to the highest levels of government. That includes those in the White House. We have been engaged for almost a decade in the wars of Afghanistan. With boots on the ground and technology we could have wiped out the largest opium production but that opportunity was lost and the price of opiates is down and supply is up.