A failed drug war and lax U.S. gun regulations spell out disaster for Mexico.

On May 18, the country awoke to news of yet another school shooting. This one occurred in Santa Fe, Texas, a small town outside of Houston. A 17-year-old shooter killed 10 high school students with his father’s gun, just months after 17 students were killed at Parkland High School. The recent shootings have rekindled a national conversation about the disproportionate levels of gun violence in the United States and the lax laws regulating gun purchase and use.

Yet missing from the mainstream conversation is an examination of how the U.S. government’s gun policies exacerbate violence in neighboring countries, particularly Mexico. Some 70 percent of guns recovered in Mexico in the last five years originated in the United States. Some of these guns come from the legal transfer of hundreds of millions of dollars in guns to Mexican police…