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.

Neither his claim that border crossings are an unchecked “invasion” nor his depiction of drugs pouring across an unguarded border has any basis in federal data.