The international war against the black market trade in narcotics seems to be at a tipping point, as a new approach is gaining traction globally: decriminalization. More and more policymakers are coming to the view that it is wrong to jail drug users as criminals.

Last November, Massachusetts voters approved a referendum that decriminalized marijuana. In December 2007, voters in Denver approved a law that made adult marijuana possession the city’s “lowest law-enforcement priority.” In California, Gov. Arnold Schwarzenegger announced it is time to closely study the decriminalization of marijuana, which is already the state’s largest cash crop.

American policy makers seem to be cautiously following the shift in public opinion on drug policy. A recent Zogby poll showed that 52 percent of those polled thought marijuana should be legal, taxed and regulated. The shift is probably the result of experience: Many Americans have either used drugs or have relatives or friends who have tried marijuana or other drugs and do not see their friends and loved ones as criminals.

More people are asking why some drug users have to be jailed while other users (such as Olympic champion Michael Phelps) maintain successful, even flourishing careers.

Drug policy reform is moving even faster abroad. In 2001, Portugal decriminalized all drugs, including cocaine and heroin. Not only has the predicted spike in drug use and a public health crisis failed to materialize, Portugal’s drug usage rates compare more favorably than many other European states that have kept up a strict “lock ‘em up” approach.

In Latin America, policymakers impressed by the experience of Portugal and other countries have begun to move in that direction. Earlier this year, a commission headed by three former Latin American presidents — Fernando Henrique Cardoso of Brazil, César Gaviria of Colombia and Ernesto Zedillo of Mexico — called on the governments of the region to break the taboo of discussing alternative drug policies such as decriminalization.

Just recently, Argentina hosted the first Latin American Conference on Drug Policies, a high-profile event sponsored by, among others, the United Nations, the Pan-American Health Organization and the Anti-Drug Latin American Initiative on Drugs and Democracy. The participants, including high-ranking government officials and experts from the region, labeled the war on drugs a failure and suggested a more pragmatic approach to drug policy based on decriminalizing possession for personal consumption.

During the event, Anibal Fernandez, chief of staff for Argentine President Cristina Fernandez, announced that her administration will be submitting a decriminalization bill to Congress in the upcoming months. An Ecuadorean official said similar legislation will soon be debated in that country’s National Assembly. Brazil is considering similar changes.

Mexico recently decriminalized possession of any drug so long as the amounts were small enough to indicate personal use. The Supreme Court of Argentina recently ruled that it is unconstitutional to punish marijuana users if no other person is harmed by such use.

There is no ideological common denominator among those questioning the war on drugs. Both liberal and conservative policymakers are dissatisfied with the gang violence that pervades the black market and the futility of trying to stop adults who wish to use drugs from doing so.

We seem to have finally reached a tipping point where the costs of the drug war clearly exceed any perceived benefit. Drug addiction is a problem. But just as alcohol prohibition was a mistaken approach to the problem of alcoholism, so too is the drug war a mistaken approach to drug abuse.