To prevent smaller criminal groups from growing and eventually competing with them, cartels also control other activities like human trafficking, kidnapping, music and software piracy, extortion and prostitution.

And to protect their huge profits, they kill competitors, journalists, policemen and innocents. My friend Maria, mother of a 14-year-old son, temporarily fled her low-income neighborhood in the city of Monterrey with her family when she realized a cartel was forcing boys to join the business. Two nights after their return, armed men entered her house and killed her son in front of her in retaliation.

While Mexico endures these atrocities, Americans are spending billions of dollars on illegal drugs. Exact figures for an illicit market are hard to obtain but estimates put the number at over $150 billion per year — more than the federal government spends on education, and four times as much as it spends on law enforcement. And Mexican cartels control virtually all of the American market, according to the Drug Enforcement Administration.

If cartels continue to have an incentive of that magnitude, our governments will never be able to put an end to the violence.

That’s why Americans must recognize that every time they buy illegal drugs they reward the cartels. If you think one person’s consumption is too small to make a difference, consider that $100 — what a recreational cocaine user might spend on a single weekend — buys the cartels 500 rounds of ammunition; $500 buys a new AR-15 rifle; $700 covers the monthly salary of one of their gunmen.

Without the vast profits from the drug trade, cartels would be infinitely less powerful, and our governments could neutralize them.

If you use illegal drugs, even just occasionally, please reconsider. Lives are at stake. Go for legal vices if you must. Even if you never use illegal drugs, you probably know people who do. Tell them about the trail of blood that led to their night of partying. If they had seen it firsthand, as I have, they wouldn’t buy those drugs.

We can shatter the misconception that recreational drug use is a victimless crime. We must put an end to the hypocrisy that allows people to make purchases based on their concerns about the environment, workers’ rights or animals — but not about killing people in Mexico.