MEXICO CITY — After 40 years, the United States’ war on drugs has cost $1 trillion and hundreds of thousands of lives, and for what? Drug use is rampant and violence even more brutal and widespread.

Even U.S. drug czar Gil Kerlikowske concedes the strategy hasn’t worked.

“In the grand scheme, it has not been successful,” Kerlikowske told The Associated Press. “Forty years later, the concern about drugs and drug problems is, if anything, magnified, intensified.”

This week President Obama promised to “reduce drug use and the great damage it causes” with a new national policy that he said treats drug use more as a public health issue and focuses on prevention and treatment.

Nevertheless, his administration has increased spending on interdiction and law enforcement to record levels both in dollars and in percentage terms; this year, they account for $10 billion of his $15.5 billion drug-control budget.

Kerlikowske, who coordinates all federal anti-drug policies, says it will take time for the spending to match the rhetoric.

“Nothing happens overnight,” he said. “We’ve never worked the drug problem holistically. We’ll arrest the drug dealer, but we leave the addiction.”

His predecessor, John P. Walters, takes issue with that.

Walters insists society would be far worse today if there had been no War on Drugs. Drug abuse peaked nationally in 1979 and, despite fluctuations, remains below those levels, he says. Judging the drug war is complicated: Records indicate marijuana and prescription drug abuse are climbing, while cocaine use is way down. Seizures are up, but so is availability.

“To say that all the things that have been done in the war on drugs haven’t made any difference is ridiculous,” Walters said. “It destroys everything we’ve done. It’s saying all the people involved in law enforcment, treatment and prevention have been wasting their time.”

In 1970, hippies were smoking pot and dropping acid. Soldiers were coming home from Vietnam hooked on heroin. Embattled President Richard M. Nixon seized on a new war he thought he could win.

“This nation faces a major crisis in terms of the increasing use of drugs, particularly among our young people,” Nixon said as he signed the Comprehensive Drug Abuse Prevention and Control Act. The following year, he said: “Public enemy No. 1 in the United States is drug abuse. In order to fight and defeat this enemy, it is necessary to wage a new, all-out offensive.”

His first drug-fighting budget was $100 million. Now it’s $15.1 billion, 31 times Nixon’s amount even when adjusted for inflation.

Using Freedom of Information Act requests, archival records, federal budgets and dozens of interviews with leaders and analysts, the AP tracked where that money went, and found that the United States repeatedly increased budgets for programs that did little to stop the flow of drugs. In 40 years, taxpayers spent more than:

$20 billion to fight the drug gangs in their home countries. In Colombia, for example, the United States spent more than $6 billion, while coca cultivation increased and trafficking moved to Mexico – and the violence along with it.

$33 billion in marketing “Just Say No”-style messages to America’s youth and other prevention programs. High school students report the same rates of illegal drug use as they did in 1970, and the Centers for Disease Control and Prevention says drug overdoses have “risen steadily” since the early 1970s to more than 20,000 last year.

$49 billion for law enforcement along America’s borders to cut off the flow of illegal drugs. This year, 25 million Americans will snort, swallow, inject and smoke illicit drugs, about 10 million more than in 1970, with the bulk of those drugs imported from Mexico.

At the same time, drug abuse is costing the nation in other ways. The Justice Department estimates the consequences of drug abuse – “an overburdened justice system, a strained health care system, lost productivity, and environmental destruction” – cost the United States $215 billion a year.

Harvard University economist Jeffrey Miron says the only sure thing taxpayers get for more spending on police and soldiers is more homicides.

“Current policy is not having an effect of reducing drug use,” Miron said, “but it’s costing the public a fortune.”

In 1970, proponents said beefed-up law enforcement could effectively seal the southern U.S. border and stop drugs from coming in. Since then, the U.S. used patrols, checkpoints, sniffer dogs, cameras, motion detectors, heat sensors, drone aircraft – and even put up more than 1,000 miles of steel beam, concrete walls and heavy mesh stretching from California to Texas.

None of that has stopped the drugs. The Office of National Drug Control Policy says about 330 tons of cocaine, 20 tons of heroin and 110 tons of methamphetamine are sold in the United States every year — almost all of it brought in across the borders. Even more marijuana is sold, but it’s hard to know how much of that is grown domestically, including vast fields run by Mexican drug cartels in U.S. national parks.

The dealers who are caught have overwhelmed justice systems in the United States and elsewhere. U.S. prosecutors declined to file charges in 7,482 drug cases last year, most because they simply didn’t have the time. That’s about one out of every four drug cases.

The United States has in recent years rounded up thousands of suspected associates of Mexican drug gangs, then turned some of the cases over to local prosecutors who can’t make the charges stick for lack of evidence. The suspects are then sometimes released, deported or acquitted. The U.S. Justice Department doesn’t even keep track of what happens to all of them.

In Mexico, traffickers exploit a broken justice system. Investigators often fail to collect convincing evidence – and are sometimes assassinated when they do. Confessions are beaten out of suspects by frustrated, underpaid police. Judges who no longer turn a blind eye to such abuse release the suspects in exasperation.

In prison, in the U.S. or Mexico, traffickers continue to operate, ordering assassinations and arranging distribution of their product even from solitary confinement in Texas and California. In Mexico, prisoners can sometimes even buy their way out.

The violence spans Mexico. In Ciudad Juarez, the epicenter of drug violence in Mexico, 2,600 people were killed last year in cartel-related violence, making the city of 1 million across the Rio Grande from El Paso, Texas, one of the world’s deadliest. Not a single person was prosecuted for homicide related to organized crime.

And then there’s the money.

The $320 billion annual global drug industry now accounts for 1 percent of all commerce on the planet.

A full 10 percent of Mexico’s economy is built on drug proceeds — $25 billion smuggled in from the United States every year, of which 25 cents of each $100 smuggled is seized at the border. Thus there’s no incentive for the kind of financial reform that could tame the cartels.

“For every drug dealer you put in jail or kill, there’s a line up to replace him because the money is just so good,” says Walter McCay, who heads the nonprofit Center for Professional Police Certification in Mexico City.

McCay is one of the 13,000 members of Medford, Mass.-based Law Enforcement Against Prohibition, a group of cops, judges, prosecutors, prison wardens and others who want to legalize and regulate all drugs.

A decade ago, no politician who wanted to keep his job would breathe a word about legalization, but a consensus is growing across the country that at least marijuana will someday be regulated and sold like tobacco and alcohol.

California voters decide in November whether to legalize marijuana, and South Dakota will vote this fall on whether to allow medical uses of marijuana, already permitted in California and 13 other states.