Executive summary
Over the past several decades, the U.S. opioid epidemic has spanned four phases:
Oversupply of prescription opioids in the 1990s.
A significant increase in heroin supply and use in the 2000s.
A supply-driven explosion of fentanyl use after 2012.
Most recently, polydrug use, with fentanyl mixed into/with all kinds of drugs.
Since fentanyl entered the U.S. illegal drug market, more than a million people in the United States have died of opioid overdose.
The costs of fentanyl use go beyond the tragic deaths and drug-use-related morbidity, however. In addition to having significant implications for public health and the economy, the fentanyl crisis intersects in many ways with U.S. foreign policy.
U.S. overdose deaths began declining in 2023. But there is little certainty as to which domestic- or foreign-policy interventions have been crucial drivers. The wider availability of overdose-reversal medication is fundamental, as is expanded access to evidence-based treatment. It is also possible that the Biden administration’s actions toward international supply from Mexico and China are contributing to this reduction in overdose deaths: since the start of 2024, China has become more active in suppressing the flow of precursor chemicals, and Mexican cartels, perhaps purposefully, are now trafficking a less lethal version of fentanyl. A wide array of policy measures as well as structural factors outside of policy control could be cumulatively and interactively reducing mortality.
The fact that the declines in mortality are not uniform across U.S. ethnic, racial, and social groups or geographic areas suggests the importance of access to medication for overdose reversal and the treatment of opioid use disorder, as well as the influence of structural factors. There is strong bipartisan support for preserving access to medication-based treatments. But crucially, access depends on medical insurance coverage, such as that provided through Medicaid and the Affordable Care Act. There are strong ideological divides about the financing and structure of the U.S. insurance industry as well as other aspects of drug policy.
On February 1, President Donald Trump imposed a 25% tariff on imports from Mexico and Canada and a 10% tariff on imports from China until each country stops the flow of fentanyl (as well as migrants, in the cases of Mexico and Canada).1 He gave all three countries a month-long reprieve before implementing the tariffs in March to see if they satisfied his counternarcotics demands. Canada adopted a robust package of anti-fentanyl measures. Mexico too tried to appease the United States through a set of law enforcement actions, though it held out on perhaps the most important form of cooperation—expanding the presence and mandates of U.S. law enforcement agents in Mexico to levels at least approaching those enjoyed during the Felipe Calderón administration.
Unlike Mexico or Canada, China did not take any further counternarcotics actions and instead responded with counter-tariffs of its own, even as Trump threatened to add additional tariffs on imports from China of up to 60%.2 On March 4, 2025, Trump dismissed Canada’s and Mexico’s law enforcement actions as inadequate, implementing the 25% tariffs. He also added an additional 10% tariff on China, meaning the second Trump administration has now placed a 20% tariff on Chinese goods.3
Apart from increasing the cost of goods for U.S. customers and driving up inflation, these tariffs will have complex effects on anti-fentanyl cooperation. Any large U.S. tariffs on China will likely eviscerate Beijing’s cooperation with the United States, resetting the diplomatic clock back to the bargaining of 2018 and noncooperation of 2021-2023. As crucial as it is to induce the government of Mexico to start robustly and systematically acting against Mexican criminal groups, whose power has grown enormously and threatens the Mexican state, Mexican society, and U.S. interests, Mexico has no capacity to halt the flow of fentanyl. Mixing the issues of migration and fentanyl risks Mexico appeasing the United States principally on migration while placating it with inadequate anti-fentanyl actions. Further, U.S. military action in Mexico, which has been threatened by Republican politicians close to Trump, would yield no sustained weakening of Mexican criminal groups or fentanyl flows. It would, however, poison the political atmosphere in Mexico and hinder its meaningful cooperation with the United States.
Strong law enforcement cooperation with Canada is crucial. Canada has been facing law enforcement challenges, such as the expansion of Mexican and Asian organized crime groups and money laundering operations in Canada. But disregarding the domestic and collaborative law enforcement efforts Canada has put on the table is capricious.
At home, Trump’s favored approach, which renews focus on imprisoning users and drug dealers, and dramatically toughening penalties for the latter, would be ineffective and counterproductive. And while providing treatment is very important, the dramatic effect of treatment modality on effectiveness cannot be overlooked. Approaches to treatment should be designed based on evidence, not ideology.