President Donald Trump says a primary reason for his new tariffs against the United States’ three largest trading partners is what he calls a “national emergency” brought on by fentanyl flowing across the country’s borders.

Trump says he is holding Canada, China and Mexico accountable for the spread of contraband drugs, but the tariffs come as the fentanyl epidemic is showing glimmers of improvement, drug policy experts and economic researchers say.

They fear that the 25% tariff on nearly all goods from Mexico and Canada and 20% on all Chinese imports will only erode the international cooperation needed to thwart global drug trafficking operations.

“Tariffs are not the sharpest tool in terms of negotiating with other countries and getting them to go along with drug and border policies,” said Bob McNab, chair of the economics department at Old Dominion University in Virginia. “This is akin to having a fence-line dispute with your neighbor and taking a sledgehammer with you.”

After years of rising overdose deaths, the United States recorded 87,000 drug overdose deaths from October 2023 to September 2024, a decrease from 114,000 the previous year, according to preliminary data from the Centers for Disease Control and Prevention.

That was the lowest overdose death toll in any 12-month period since June 2020, the CDC said. Overdose deaths surpassed more than 100,000 for the first time in 2021, with the majority linked to synthetic opioid use. The crisis has devastated small communities and urban centers alike.

Vanda Felbab-Brown, who studies international organized crime as a senior fellow at the Brookings Institution, a nonprofit think tank, cited two major factors that have helped curb fentanyl’s devastating effects in the United States: law enforcement efforts during the Biden administration to combat the fentanyl production pipeline in China and Mexico and the widespread availability of the overdose reversal medication naloxone.

“These are potentially very ephemeral, but they all predate the tariffs,” she said.

In addition, law enforcement has continued to confiscate fentanyl at the border. About 21,900 pounds of the drug were seized in the 2024 fiscal year. That’s down from over 27,000 in fiscal year 2023 but up from the 14,700 in 2022, according to Customs and Border Protection.

Nearly all of that fentanyl was taken at the U.S. southern border. In the current fiscal year, just 10 pounds have been recovered along the Canadian border to date, compared with 5,400 along the Mexican border, CBP data shows.

Canadian Prime Minister Justin Trudeau balked at Trump’s tariffs, saying Tuesday that there was “no justification” for them because “less than 1% of the fentanyl intercepted at the U.S. border came from Canada.”

Last month, after Trump first threatened to impose tariffs, Trudeau announced that he would appoint a “fentanyl czar” and designate cartels as terrorist organizations.

Mexican President Claudia Sheinbaum, who assumed office in October, has also tried to work with the Trump administration by amassing thousands of her country’s troops along the border last month to snuff out drugs. Sheinbaum has been aggressive with Mexico’s drug cartels, deploying troops to go after such crime in the state of Sinaloa.

Sheinbaum said Mexico would respond to Trump’s tariffs by Sunday. Canada and China have already announced retaliatory tariffs on certain U.S. goods, stoking fears of an all-out trade war.

Gladys McCormick, the Moskowitz endowed chair in Mexico-U.S. relations at Syracuse University, said the tariffs may cause an “irrevocable damage of trust” between the United States and Mexico, with the latter instead leaning more heavily on China, its second-largest trading partner.

Federal prosecutors have accused China-based companies of producing and selling fentanyl precursors, which are used to manufacture the drug, and distributing them around the world, including to Mexico, where cartels create synthetic opioids.

Mexico’s leaders may still seek to negotiate with the Trump administration to prevent the Mexican economy from faltering, McCormick said.

“The consequences of pushing the Mexican economy into a forced and deep recession is that, if anything, it will actually make people have to resort to informal economic activity, which oftentimes is illicit,” she said.

Fentanyl is a powerful drug used as an anesthetic and painkiller in hospital settings. U.S. drug officials say illegal fentanyl began originating out of China about a decade ago, spreading illicitly in part as a consequence of the opioid epidemic that started with addictive painkillers like oxycontin. Fentanyl is far cheaper to produce, but it can be up to 50 times deadlier than heroin, although some versions can be less potent.

McNab said Trump’s new tariffs don’t address other ways fentanyl enters the United States, including smuggling by Americans. Americans were 80% of all people caught with fentanyl during border crossings at ports of entry from 2019 to 2024, according to CBP data obtained by the Cato Institute, a libertarian think tank.

“We would all agree it’s a laudable goal if tariffs can stop the importation of fentanyl and stop individuals crossing the border illegally into the United States,” McNab said. “But we don’t know if, at the end of the day, if all this costs us hundreds of billions of dollars in lost economic activity, is that worth the cost of less fentanyl coming across our border?”

Some states have seen the tide turn in the fentanyl crisis over recent months.

Dennis Cauchon, the founder and president of Harm Reduction Ohio, which supports progressive drug policies, said he has witnessed a drastic decline in his state in fentanyl-related overdose deaths over the past two years. State officials say Ohio has been outperforming the national decline by expanding naloxone distribution and treatment services.

Cauchon also attributes the 2023 breakup of the top leadership of the Sinaloa Cartel, once led by kingpin Joaquín “El Chapo” Guzmán Loera, for disrupting the fentanyl market.

“Tariffs may get the credit in the future, but the reality is fentanyl has been declining at historic levels for two years,” Cauchon said. “Whether that continues is hard to guess.”