U.S. President-elect Donald Trump's vow to impose tariffs on China and Mexico unless they stem the flow of fentanyl and migrants across the U.S. border could impel deeper cooperation from those governments on drug policing,

This fantasy that you could stop fentanyl by attacking the precursors is fraught with danger," an expert tells Filter.

The president-elect’s pledge to use tariffs to stem the flow of opioids from China could backfire if Beijing responds by ending counternarcotics cooperation.