In an article over at CNN​.com, I discuss a new study that confirms that the war on drugs is an expensive failure. That report from BMJ Open, an affiliate of the British Medical Journal, reaches the damning conclusion, supported by compelling evidence, that drug warriors have consistently failed to achieve their stated objectives.

Among other findings, the report documents that inflation‐​adjusted and purity‐​adjusted prices of marijuana, cocaine, and heroin have all decreased dramatically since 1990. That was true in such geographically distinct areas as Europe, the United States, and Australia. In other words, illegal drugs are plentiful and cheap around the world, and there is no indication that the trend is likely to change. The authors state that despite “increasing investments in enforcement‐​based supply reduction efforts aimed at disrupting global drug supply, illegal drug prices have generally decreased while drug purity has generally increased.”

None of this comes as a surprise to the swelling ranks of critics of the international drug prohibition policy. Drug abuse is certainly a major public health problem, and its societal costs are considerable. But banning the drug trade creates ugly social and economic distortions. Because certain drugs are illegal, there is an enormous black‐​market premium (by most estimates, up to 90 percent of the retail price) associated with them. That lucrative lure attracts the most corrupt, violent individuals and organizations.

As the BMJ Open study notes, the international drug trade is a $350 billion a year industry. There is no realistic way to suppress such an economic juggernaut. We can only determine whether the trade will be in the hands of honest businesses or ruthless criminals. The quixotic U.S. crusade against alcohol in the 1920s and early 1930 empowered gangsters like Al Capone and Dutch Shultz. Bootleggers bribed and corrupted elected officials and police personnel throughout the country. There were shootouts on the streets of Chicago, New York, and other American cities—just as we have gun battles between drug gangs in numerous cities today. Once Prohibition ended, legitimate business provided consumers with the beverages they sought, and the carnage and corruption subsided.

We need to recognize that our second fling with prohibition, this time with respect to such drugs as marijuana, cocaine, and heroin, hasn’t worked any better than the first. Indeed, the current version has led to even worse consequences. It is well past time to terminate the futile, disastrous war on drugs. The BMJ Open study gives an abundance of new evidence why the United States needs to set a good example and lead the world away from the folly of drug prohibition.