Tariff threats take aim at fentanyl trafficking. Here’s how the drug reaches the US Boston 25 News [Video]

President Donald Trump’s plan to impose tariffs on goods from Mexico, Canada and China is partly aimed at combating the illicit flow of fentanyl into the U.S., where the opioid is blamed for some 70,000 overdose deaths annually.

Mexico agreed Monday to send 10,000 troops to the U.S.-Mexico border as part of a deal with Trump to pause the tariffs for a month — and hold off levying its own.

Neither Canada nor China has signaled major changes to tackle the flow of fentanyl into the U.S., and each has said it would retaliate for any U.S. tariffs.

What role do Mexico, Canada and China play in fentanyl reaching the U.S.? And how much can their governments do?

Where does fentanyl come from?

The ingredients in fentanyl are largely produced by companies in China and used by pharmaceutical companies to make legal painkillers. But a portion of those chemicals is purchased by the Sinaloa and Jalisco cartels in Mexico.

Cartels …