The model fell out of favor as the war on drugs took off under President Richard Nixon and governments instated zero-tolerance prohibition and abstinence-only treatment programs. By the early 1980s, federal funding for addiction research and treatment in the U.S. was contingent on the promotion of abstinence-only models. Researchers preaching alternative approaches found themselves attacked and ostracized.

Harm reduction is not a new concept, although, given the efforts to exclude it from policy discussion, one could be forgiven for thinking so. In its modern form, the philosophy was born out of the responsible-use movement of the 1960s, which sought to educate users on safe ingestion methods and avoiding tainted drugs. (Think of the famous broadcast at Woodstock warning revelers to stay away from the “brown acid.”)

As a result of these warped priorities, a third of injecting drug users in some areas of sub-Saharan Africa are infected with HIV. Globally, only 8 percent of opioid addicts have access to methadone or buprenorphine, potentially life-saving substitutes that can be administered at a low cost.

UNAIDS , a United Nations effort to increase access to HIV prevention and treatment, disburses only about $160 million a year to prevent blood-borne infections in drug users, while the United States alone spends $50 billion annually on drug interdiction and enforcement. HRI estimates that if the world spent just a tenth of its enforcement budget on harm-reduction practices, it could “fill the gap in HIV and hepatitis C prevention among people who use drugs twice over.”

A recent report from the U.K.-based group Harm Reduction International (HRI) warns that the measurable benefits of harm reduction can be realized only through a fundamental shift away from a law enforcement approach to drug use.

But harm reduction is still far from a consensus view. A recent outbreak of HIV in Indiana , tied to a lack of access to clean needles, demonstrates that in many places public health considerations are outweighed by punitive drug policy and enduring stigma against drug users.

The harm reduction approach focuses on mitigating the adverse consequences of drug use rather than attempting to eliminate it. As policymakers confront the futility of drug prohibition, the two primary harm reduction practices — clean needle exchanges for intravenous drug users and medication-assisted treatment for addicts — are more widespread today than ever before. The United Nations Commission on Narcotic Drugs has endorsed harm reduction, and the International Drug Policy Consortium has brought together 134 NGOs to promote evidence-based practices that reduce the risk of injury and premature death for drug users. Last year nearly a dozen U.S. states passed laws allowing for the distribution of the opioid blocker naloxone to laypeople, and a number of others passed good-Samaritan laws providing immunity from some criminal penalties for those who call emergency services to report a drug overdose.

Today marks the second annual International Harm Reduction Day, a collaborative effort by medical experts, drug-reform advocates and dozens of associated nongovernmental organizations to draw attention to the most promising alternative to the war on drugs.

Regulations prevent many people from getting the treatment they need, particularly in rural America, where access to methadone is almost nonexistent.

As harm reduction fell from favor, the disease theory of addiction became dominant. That theory helped reduce the stigma around alcoholism and drug addiction. However, it also promoted the idea — now accepted as medical fact — that compulsive behavior tied to drug or alcohol use is unmanageable short of total abstinence and that a problem with one substance translates into a de facto problem with all of them. (Imagine if we held compulsive eaters to the same strict scrutiny.) Such inflexible thinking and the conflation of abuse and addiction have created an environment in which helping drug users mitigate the harm of their use is widely considered as dubious as telling cancer patients to smoke less.

The emergence of HIV in the mid-1980s and the decadelong AIDS crisis that followed broke down the resistance to harm reduction. From 1984 to 1990, 14 European nations launched needle exchange programs, the majority of them publicly funded. By last year, that number had grown to 90. Yet we have barely scratched the surface of harm reduction’s potential to improve the lives of millions of people around the world.

The U.S. in particular has lagged behind other developed nations. Drug policy reformers have recently expressed optimism about President Barack Obama’s new drug czar, Michael Botticelli, a recovering alcoholic who has promised to champion harm reduction efforts. However, it’s unclear whether Botticelli has the power to make more than cosmetic changes.

Many U.S. laws run counter to harm reduction principles, and fixing them will require action by Congress. Thirty-three U.S. states and the District of Columbia allow needle exchange programs, but federal law prohibits the use of taxpayer dollars to pay for the programs, keeping North America far behind Europe and Australasia in the number of clean syringes distributed per user.

While opioid substitution therapy is available at more than 2,400 facilities in the 50 states, federal restrictions prevent doctors from prescribing methadone and limit the distribution of suboxone. Along with funding disparities, these regulations prevent many people from getting the treatment they need, particularly in rural America, where access to methadone is “almost nonexistent,” according to a paper published last year by the Journal of the American Medical Association.

Despite having the largest prison population in the world — including the highest percentage of inmates who inject drugs — harm reduction in U.S. prisons is extremely limited, and hepatitis C runs rampant in the U.S. prison system. A handful of prisons and jails provide opioid substitution therapy to inmates, but most limit access to inmates who happened to enter the system already on methadone or suboxone.

Taking principles of harm reduction to their logical conclusion would require rethinking prohibition itself. History has demonstrated that outlawing one drug serves only to open a pathway for other, often more dangerous, substances. The deadly bathtub gin of 1920s Prohibition is paralleled today by synthetic drugs manufactured in makeshift labs or in unregulated industrial plants in China. Last year dozens of people in the U.S., Canada and Britain were sickened, many of them fatally, by an impure derivative of MDMA, a drug that in its purest form can be used relatively safely if certain precautions are taken.

More recently, a wave of poisonings tied to the synthetic cannabinoid K2 sent youths in several states to emergency rooms. K2 was blamed for eight deaths in Pennsylvania in April. A harm-reduction approach would recognize that legal marijuana — which has never been blamed for a single toxicity death — is far preferable to legal poison.

But perhaps no harm-reduction strategy would have more widespread impact on American communities than ending the war on drugs. A glimpse at the arrest record of Freddie Gray — whose death in police custody sparked the Baltimore riots — shows that of 18 charges dating to 2007, all but two were for low-level drug offenses. Imagine all the harm that could have been avoided if he had not been criminalized in the first place.