As the rest of the country looks to undo mass incarceration, two former drug czars say it's time to "bring back the war on drugs."

Bill Bennett and John Walters — who led the Office of National Drug Control Policy for Presidents George H.W. Bush and George W. Bush, respectively — argued in the Boston Globe on Tuesday that President Barack Obama's administration has effectively abandoned the war on drugs, letting heroin use run rampant in the US.

Their claims are summarized in one sentence from the piece:

Now drug gangs flourish in a legalized-drug environment, spreading addiction throughout America.

The sentence reveals the two biggest myths in Bennett and Walters's op-ed: that Obama has in any way ended the war on drugs, and that the drug war helped effectively combat drug abuse in the first place. The truth is much more complicated — and crucial to understanding the administration's approach to the nation's heroin problem.

The Obama administration has generally spent more on the war on drugs than the Bush administration

Bennett and Walters claim that the Obama administration has scaled back the war on drugs, creating what they call "a legalized-drug environment." This is blatantly false: Marijuana, heroin, meth, crack, and powder cocaine are all illegal at the federal level, just like they were when Obama took office. Obama has said that he opposes legalizing any drug, including pot, although his administration has not cracked down on states that legalized marijuana.

Bennett and Walters's claim appears to be rooted in the belief that the Obama administration has abandoned the traditional branches of the war on drugs: law enforcement and interdiction efforts, which aim to disrupt drug supplies across the globe by going after drug producers and traffickers. But this is also wrong: According to federal data, anti-drug spending on both of these strategies has been generally higher under Obama than it was under Bush.

Spending on law enforcement and interdiction efforts has remained relatively flat in recent years — a trend that's generally true for all federal discretionary spending. But the federal government still dedicates a lot to traditional drug war efforts: around $15 billion each year. And it's gradually increased anti-drug spending for treatment and rehabilitation programs. For better or worse, the war on drugs is far from over.

The war on drugs was never good at eliminating supply

Bennett and Walters look back with fondness at the history of the drug war, writing that "programs to reduce production, interdict the drugs, and lead international partnerships to destroy drug cartels" were part of a successful anti-drug strategy.

This claim can be empirically measured. If the US and its anti-drug partners around the world were successful in squashing the supply of drugs, then the price of these substances would have gone up. It's basic economics: All other things being equal, reduced supply leads to higher prices. (This is, in fact, the explicit economic goal of the drug war: By making drugs more expensive, the thinking goes, they will become a less affordable habit.)

Yet the federal data shows the opposite occurring, with prices for heroin in particular crashing over the past few decades.

The numbers we have on supply back this up. A 2015 report by the UN Office on Drugs and Crime (UNODC) found that the production of opium, which is used to make heroin, has generally trended up since the late 1990s — with a brief drop in 2001 after the invasion of Afghanistan, the world's largest opium producer.

Not only has the drug war failed to reduce the global production of opium, but, the UNODC report notes, production in 2014 reached its second highest levels since the 1930s. That's despite concerted US efforts in Afghanistan to crack down on the drug: The US spent $7.6 billion between 2002 and 2014 to eliminate Afghani poppy cultivation.

"The bottom line — record opium cultivation and production — clearly shows we are not winning the war on drugs in Afghanistan," John Sopko, the US military's watchdog in Afghanistan, said in a May 5 speech. "Of course, the US government announced its own war on drugs in 1971, almost 45 years ago, and we haven't won that, either."

So despite billions in spending, the war on drugs never appeared to have a significant impact on the supply or price of the drug — heroin — that Bennett and Walters claim we need a new drug war to fight.

That doesn't necessarily mean that the war on drugs had zero impact. It's possible that it reduced supply and raised prices, just not enough to reverse larger trends.

But that's exactly the problem: If the costly drug war wasn't enough to reverse these trends, then maybe it's worth trying something else, like putting more money toward reducing demand for drugs by treating drug abuse as primarily a public health issue.

There is a crisis with prescription painkillers and heroin

Bennett and Walters focus much of their concern on the rising problem of heroin and opioid painkiller abuse. This is a real problem — but it goes back to the 1990s, not to the current White House.

Since the late 1990s, the number of people dying from opioid painkiller overdoses has steadily risen — with more than 16,000 deaths reported in 2013. Faced with this issue, the Obama administration began cracking down on opioid painkillers by going after doctors who loosely prescribed the drugs.

But as this study in JAMA Psychiatry found, this actually pushed painkiller users to heroin, another opioid that is cheaper and more accessible, despite being illegal. (A Centers for Disease Control and Prevention analysis backed this up: People who are addicted to prescription painkillers are 40 times more likely to be addicted to heroin.)

The public and experts don't want a war on drugs

That this crisis is happening at all is a testament to the drug war's failure. The federal government managed to crack down on the legal drug (opioid painkillers) by going after legal actors and enforcing new regulations. But it's failed to keep the illegal drug (heroin) inaccessible and unaffordable, in large part because it's too hard to contain the underground drug market.

Given these failures, the Obama administration is keeping tough-on-drug spending roughly the same, but also turning to public health programs to treat opioid addiction — an idea widely endorsed by public health and drug policy experts and the public.

So the "heroin epidemic," as Bennett and Walters call it, is rooted in the failure of previous administrations — including the administrations they served under — to crack down on opioid painkillers before too many prescriptions led to a new population of addicts. And the Obama administration is now trying to fix the mess it's left behind. But instead of only trying the same failed approach of the past few decades, it's also trying to take more of a public health role. That's not abandoning the war on drugs; it's adapting to the history and data.