For the past seven months, debates about U.S.-Latin America relations have focused almost exclusively on two topics: Cuba and Venezuela. Analysts have been debating whether our new policies toward these countries—normalization of relations with the former, sanctioning of leaders in the latter—will help or hurt our national security.

These are no doubt vital topics. But in many ways, they are diversions.

The most serious security threat in the Americas is bigger and broader than any of our bilateral relations in the region. The real threat is the continued expansion of violent crime in most of Latin America, especially north of the Equator. And the United States continues to be blind about one of the ways in which it is contributing to this crisis, namely our lax gun controls.

Critics of our lax gun policies in the United States rightly point out that gun availability is worsening security in our own country. What they often fail to mention is that it is also feeding the most intense wave of violence this hemisphere has seen since perhaps the early 20th century.

Latin America and the Caribbean (LAC) is the region with the most homicides in the world (with 14 of the 20 countries with the highest homicide rates) and the only region where homicide rates have been increasing annually for the past decade. LAC accounts for almost one-third of the total homicides in the world but only eight percent of the world’s population.

This violence is, of course, a Latin American problem, but not entirely. It is also a U.S. problem. Because our allies in the region are besieged by this violence, we are increasingly investing resources and personnel to help them fight it. Since 2008, Congress has appropriated $2.5 billion for the Mérida Initiative, counterdrug and anticrime assistance programs, to help Mexico, an additional $248 million for Central America, and $42 million for the Caribbean. In 2015, the Obama administration announced it would ask Congress to appropriate $1 billion in its budget for Central America.

Yet, even with those investments, the violence in the region continues to grow.

Crime and violence are now probably the most important drivers of immigration from the region. Whereas political strife and economic despair were the most important drivers of immigration from Central America in the 1980s and early 1990s, people are now fleeing north to avoid insecurity. A study by the American Immigration Council during last summer’s huge influx of unaccompanied children crossing the U.S.-Mexico border found that 59 percent of boys and 61 percent of girls named “crime, gang threats, or violence” as a reason for their emigration.

The spread of violent crime in Latin America has multiple causes. Some people blame hard-to-control market forces: the expansion in both the demand and supply of drugs. Others blame shifts in the narcotics trade: the de-monopolization of drug trafficking, leading to criminal organizations that fight among themselves for control of routes and markets. Still others blame Latin American countries directly: the weakness of Latin America’s own courts and law enforcement units that are ill-equipped to prosecute and solve crimes, creating a climate of impunity that encourages crime. And finally, there are those who blame the United States: our penchant for focusing on militarizing our response to crime and deporting too many criminals, who then turn to crime once they make it back home.

All these factors play a role. But missing from this discussion is awareness of the role of U.S. gun laws. Lenient gun policies allow traffickers to easily acquire a high volume of assault weapons, sniper rifles, armor-piercing handguns, etc., and smuggle them to gangs across the region. The evidence is plentiful. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) stated in 2011 that more than 90 percent of firearms seized in Mexico in the last five years were traced to the United States. This statistic is disputed but the lowest estimate of 68 percent is still alarming. The ATF also estimates that 95 percent of firearms in Mexico are bought in the U.S. and these American guns also make their way further south into the Central American countries. In 2013, 30 percent of the 2,045 firearms seized by Guatemalan law enforcement, 52 percent of 1,079 seized firearms in Ecuador, and 46 percent of 842 seized firearms in Honduras were traced directly to the United States.

The problem is not just gun availability, but also ammunition. In some states, it is harder to purchase some anti-diarrhea medicines, cold medicines, and even some over-the-counter prescriptions than to purchase ammunition for your guns. Pharmacists in 24 states are required to request some form of ID before dispensing these drugs.

In contrast, no state requires any form of ID to buy ammunition. All you need is cash or credit cards.

No doubt, an important cause of the crime wave is state and institutional failure in Central and South American nations. But the U.S. also lacks capacity in its own territory regarding drugs and guns. As the main bureau in charge of investigating gun crimes and trafficking in the U.S., the Bureau of Alcohol Tobacco, Firearms and Explosives (ATF) is stretched thin. Today, for instance, the ATF has more or less the same number of agents (2,500) as in the early 1970s. In contrast, we have increased the number of agents working for the FBI (from 8,700 to 13,000 in 1973), the DEA (from 1,500 to 5,000), and the U.S. Marshals program (from 1,900 to 3,300).

Lack of institutional resources is limiting the effectiveness of the ATF. In 2004, the ATF was only able to inspect 4.5 percent of U.S. gun dealers. Of the narrow sample of gun dealers inspected, from 2004 to 2011, the ATF uncovered almost 175,000 firearms missing from inventories. In 2012, the ATF only inspected 19 percent of US gun dealers. Of the 19 percent inspected in 2012, almost 50 percent were found to be in violation of federal regulations. On average, gun dealers are inspected once a decade.

It’s incorrect to believe that the crime explosion in Latin America is the result of only one factor. But more so than our actions in the region, it is our lack of action at home that is endangering our security and the lives of those south of us.

Better gun control in the United States, of course, won’t end this security crisis. There are too many factors at play. But the crisis has no chance of abating as long as our approach to guns and ammunition remains what it is: an unsupervised mess.

Javier Corrales is the Dwight W. Morrow 1985 Professor and Chair of Political Science at Amherst College and Abigail Xu graduated from Amherst College this spring and will be attending law school in the fall.