Other experts pointed out that past efforts to deploy military might against drug traffickers have failed to slow the flow of drugs into the United States. When the Mexican government declared war on cartels in 2006 and sent soldiers into the streets to fight them, the clearest result was a massive increase in homicides.

The CIA under President Donald Trump has been covertly flying MQ-9 Reaper drones over Mexico to spy on drug cartels, current and former officials familiar with the matter told CNN, part of Trump’s dramatic reorientation of national security assets to the US southern border.