Richard Nixon was the first to utter the phrase, and the first to usher in comprehensive federal anti-drug legislation as well. In 1969, Nixon was so outraged by the stream of marijuana coming from Mexico that he actually shut down the southern border, a tactic announced as Operation Intercept (Schaffer Library of Drug Policy). He even went so far as to refer to drug abuse as "public enemy number one," a past era's Osama bin Laden requiring complete evisceration. As a result of this rhetoric and the Comprehensive Drug Abuse Prevention and Control Act of 1970, governmental response to drugs turned in an entirely different direction indefinitely. Ever since, lawmakers have ceased to consider drug abuse a social or chemical problem to be addressed through treatment; but rather a law enforcement issue to be addressed through criminal justice. In 1973, the government created an entire federal law enforcement agency solely for the purpose of combating the drug war, the Drug Enforcement Administration (DEA). This began a four decade deadly cat and mouse game pitting law enforcement versus cartels, growers, makers, smugglers, dealers and (tragically) users that shows little sign of abating.
Proponents of strict drug laws contend that they are effective in discouraging illicit drug use because they are used by a significantly lower percentage of the population than legal substances such as alcohol and tobacco. They argue there must be criminal penalties in order to discourage using substances the contribute to societal decay and that also cause heath problems. As such, backers claim that any economic gains generated by the regulating and taxing of these drugs would be more than offset by increased heath costs and lower productivity. Because drugs can be addictive, they also point out that people can engage in sustained violent and criminal behavior due to their effects. Most who count themselves among supporters of these laws freely admit that the war on drugs can never be completely won; but you can't catch every murderer either, and they would ask if you support legalizing that.
Speaking of murder, this brings us to a very strong argument for legalization. As with all wars, less people will die if the war on drugs is brought to an end. Mexican and South American drug cartels kill countless numbers every day due to the profitable black market for drugs that only exists because of their illegal nature. The Mexican government estimates over 34,000 were killed from 2007 through 2010 in that country alone (Los Angeles Times). As former narcotics officer Michael Levine explains, "I learned that not only did they not fear our war on drugs, they counted on it to increase the market price and to weed out the smaller, inefficient drug dealers. They found U.S. interdiction efforts laughable. The only U.S. action they feared was an effective demand reduction program." Up north in the United States, the 21st amendment (repealing the 18th amendment prohibiting alcohol) coincided with an immediate drop in the nation's murder rate (The Free Library).
Still, the most convincing argument is a moral one. It is flat out reprehensible to punish people for using substances they are addicted to. Furthermore, we should all have the right to make our own mistakes and not be told by a governing body that we don't have control over our literal body. If someone wants to harm themselves, that is their individual right as a human being; and we should offer them a helping hand - not handcuffs on a wrist.