Mexican federal police in riot gear receive instructions at the border crossing between Guatemala and Mexico, in Ciudad Hidalgo, Mexico, Friday, Oct. 19, 2018. Members of a 3,000-strong migrant caravan have massed in this Guatemalan border town across the muddy Suchiate River from Mexico, as U.S. President Donald Trump threatens retaliation if they continue toward the United States. (AP Photo/Moises Castillo)

Predictably, media outlets are calling President Trump’s decision Thursday to back off a border closing the “second major climbdown this week” but this one comes with a caveat and a stern warning to Mexico: they have a year to stop the flow of drugs or face tariffs on automobiles coming into the U.S.

In remarks to reporters at the White House, Mr. Trump said Mexico wasn’t doing enough to stop the cross-border flow of illegal immigrants and illicit drugs. He said if the drug flow didn’t stop, he would level tariffs on cars coming into the U.S. from Mexico—followed by closing the border. But he also said he planned to give Mexico a year to satisfy his demands.

“We’re going to give them a one-year warning and if the drugs don’t stop, or largely stop, we’re going to put tariffs” on cars, he told reporters. “And if that doesn’t stop the drugs, we close the border.”

The U.S. is currently involved in trade negotiations with Canada and Mexico, called the United States–Mexico–Canada Agreement (USMCA), that, if passed, would prevent the U.S. from imposing auto tariffs on either nation. Trump is apparently willing to delay that agreement to stop the flow of illicit drugs into the U.S. at the Southern border.

“The USMCA is a great deal for everybody, but this is more important to me than the USMCA,” Trump told reporters Thursday.

The Drug Enforcement Administration’s 2018 National Drug Threat Assessment listed the Mexican drug cartels as the greatest illicit drug threat to the United States, and the Trump administration has repeatedly warned of how that trade has expanded the opioid epidemic.

Mexican Transnational Criminal Organizations (TCOs): Mexican TCOs remain the greatest criminal drug threat to the United States; no other group is currently positioned to challenge them. The Sinaloa Cartel maintains the most expansive footprint in the United States, while Cartel Jalisco Nueva Generacion’s (CJNG) domestic presence has significantly expanded in the past few years. Although 2017 drug-related murders in Mexico surpassed previous levels of violence, U.S.-based Mexican TCO members generally refrain from extending inter-cartel conflicts domestically.

While Trump detractors have taken issue with the idea that drugs are coming across the border via unsupervised areas, claiming most come through legal ports of entry, Trump seems to believe that regardless of how they’re entering, Mexico needs to play more of a role in controlling their movements.