Throughout its history, the United States benefited from the gift of geography.

An ocean to the east and the west, plus peaceful Canada to the north, means Americans could retreat into splendid isolationism or worry more about far-flung regions like Asia or the Middle East.

No, we didn’t forget about Mexico. Lately, the nation to our south exhibits symptoms of a failed state, with migration and violence that shakes the sense of calm that Americans enjoyed since the days of Pancho Villa or the Zimmerman telegram. In the wake of a horrific attack this month that killed nine U.S. citizens in Mexico, our country has a lot more to worry about closer to its own borders.

Some of those concerns extend all the way to Missouri. After the deadly ambush, U.S. Sen. Josh Hawley, a Republican, took Mexican officials to task for failing to combat drug cartels that are fueling violence south of the border. He accuses the Mexican government of “looking the other way” while cartels flood Missouri with meth and other drugs.

In this case, the senator diagnoses the right problem but misses the mark on the cure. He expresses justified outrage at Mexico’s light hand in fighting cartels, a form of appeasement that fuels more violence, but his suggestion to freeze assets and impose sanctions is likely to backfire. That’s because anything that weakens Mexico’s economy — and sanctions would do just that — will send migrants streaming north.

The best prescription to combat the cartelization of Mexico is to eliminate the fuel that powers that country’s criminal gangs: America’s insatiable demand for illegal drugs. The Wall Street Journal reports that Americans spent $150 billion on cocaine, heroin, methamphetamine and marijuana in 2016. That’s a 50 percent increase in five years.

Much of that money does not go to your friendly neighborhood head shop. It incentivizes the vicious lawlessness that is rampant in Mexico. This doesn’t mean it’s all our fault — that veers dangerously close to blaming the victim — but there needs to be an acknowledgment that users and dealers are complicit in what is happening.

The appalling violence in Mexico should shatter the dreamworld of consequence-free drug use in the United States. Some might believe that the war on drugs is over, but a black market for illegal marijuana still exists in states that have legalized for recreational purposes. It’s hard to imagine any society that’s better off with easier access to meth or heroin.

The best that legalization gives us is peace without victory in the war on drugs. The results are plainly visible, in the shattered lives in Missouri’s urban areas and small towns, and in the chaos to our south.