Mexico’s Long War: Drugs, Crime, and the Cartels

Mexico’s Long War: Drugs, Crime, and the Cartels

Violence continues to rage more than a decade after the Mexican government launched a war against drug cartels.
A Mexican Army expert shows crystal meth paste at a laboratory in Tecate, Mexico.
A Mexican Army expert shows crystal meth paste at a laboratory in Tecate, Mexico. Guillermo Arias/AFP/Getty Images
  • Mexican drug cartels are leading suppliers of cocaine, heroin, methamphetamine, and other illicit narcotics to the United States.
  • The cartels and the drug trade fuel rampant corruption and violence in Mexico, contributing to tens of thousands of homicides in the country each year.
  • Since Mexico launched a war on the cartels in 2006, the United States has provided it with billions of dollars in security and counternarcotics assistance.


Mexican authorities have been waging a deadly battle against drug cartels for more than a decade, but with limited success. Thousands of Mexicans—including politicians, students, and journalists—die in the conflict every year. The country has seen more than 360,000 homicides since 2006, when the government declared war on the cartels. 

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The United States has partnered closely with its southern neighbor in this fight, providing Mexico with billions of dollars to modernize its security forces, reform its judicial system, and fund development projects aimed at curbing migration at Mexico’s southern border. Washington has also sought to stem the flow of illegal drugs into the United States by bolstering security and monitoring operations along its border with Mexico.

What drugs do the cartels traffic?

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Drug Policy

Border and Port Security

Transnational Crime

Mexican drug trafficking organizations (DTOs)—sometimes referred to as transnational criminal organizations—dominate the import and distribution of cocaine, fentanyl, heroin, marijuana, and methamphetamine in the United States. Mexican suppliers are responsible for most heroin and methamphetamine production, while cocaine is largely produced in Colombia and then transported to the United States by Mexican criminal organizations. Mexico, along with China, is also a leading source of fentanyl, a synthetic opioid up to fifty times more potent than heroin. The amount of fentanyl seized by Mexican authorities nearly quintupled between 2019 and 2020.

The amount of fentanyl seized by Mexican authorities nearly quintupled between 2019 and 2020.

At the same time, the cartels smuggle vast quantities of marijuana into the United States, even though some U.S. jurisdictions have legalized it. Conversely, California’s booming cannabis industry has prompted traffickers to smuggle U.S.-grown marijuana across the border to Mexico, where lawmakers have yet to fully legalize the drug.

Which are the largest cartels?

Mexico’s drug cartels are in a constant state of flux. Over the decades, they have grown, splintered, forged new alliances, and battled one another for territory. The cartels that pose the most significant drug trafficking threats [PDF] to the United States, according to the U.S. Drug Enforcement Administration (DEA), are:

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Sinaloa Cartel. Formerly led by Joaquín “El Chapo” Guzmán, Sinaloa is one of Mexico’s oldest and most influential drug trafficking groups. With strongholds in nearly half of Mexico’s states—particularly those along the Pacific coast in the northwest and near the country’s southern and northern borders—and operations in as many as fifty countries, it has a larger international footprint than any of its Mexican rivals. In 2017, Mexican authorities extradited Guzmán to the United States, where he is serving a life sentence for multiple drug-related charges. In 2021, U.S. President Joe Biden imposed sanctions on eight members of the group, which is now led by Ismael Zambada García and El Chapo’s sons, known as “Los Chapitos.”

Jalisco New Generation Cartel (CJNG). Jalisco splintered from Sinaloa in 2010 and is among Mexico’s fastest-growing cartels, with operations in more than two-thirds of the country. According to the DEA, the “rapid expansion of its drug trafficking activities is characterized by the group’s willingness to engage in violent confrontations” with authorities and rival cartels. U.S. officials estimate that CJNG supplies more than one-third of the U.S. drug market. 

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Drug Policy

Border and Port Security

Transnational Crime

Beltrán-Leyva Organization (BLO). The group formed when the Beltrán-Leyva brothers split from Sinaloa in 2008. Since then, all four brothers have been arrested or killed, but their loyalists continue to operate throughout Mexico. The organization’s splinter groups have become more autonomous and powerful, maintaining ties to Jalisco, Juárez, and Los Zetas.

Los Zetas. Originally a paramilitary enforcement arm for the Gulf Cartel, Los Zetas was singled out by the DEA in 2007 as the country’s most “technologically advanced, sophisticated, and violent” group of its kind. It splintered from the Gulf Cartel in 2010 and held sway over swaths of eastern, central, and southern Mexico. However, it has lost power in recent years and fractured into rival wings, the most prominent being the Northeast Cartel.

Guerreros Unidos (GU). Based in southwestern Mexico, Guerreros Unidos (United Warriors) broke away from the BLO in 2009 and became involved in the heroin trade. The group is known to have a partnership with the CJNG, using the same transportation networks to move drug shipments to and from the United States.

Gulf Cartel. Its base of power is in northeast Mexico, especially the states of Tamaulipas and Zacatecas, and it is thought to be working with CJNG members in those areas. In the past decade, the group has splintered into various factions, diluting its strength as it battles for territory with Los Zetas. In 2021, three warring Gulf factions announced they had reached a truce, insisting that they wanted to maintain peace in Tamaulipas.

Juárez Cartel. A long-standing rival of Sinaloa, Juárez has its stronghold in the north-central state of Chihuahua, across the border from New Mexico and Texas. In recent years, the group has splintered into several factions, including La Línea, which controls street-level enforcement.

La Familia Michoacána (LFM). Formed in the 1980s, LFM has its base in western Mexico’s Michoacán State. In 2009, U.S. President Barack Obama designated the group’s members as “significant foreign narcotics traffickers” and imposed financial sanctions on it under the Foreign Narcotics Kingpin Designation Act. While still active, LFM has weakened and fragmented in recent years.

Los Rojos. Another splinter group of the BLO, Los Rojos operates in central and southwestern Mexico and relies largely on kidnapping and extortion. Although several of its leaders were arrested between 2019 and 2020, the group remains active, and along with Guerreros Unidos, has been linked to the 2014 disappearance and murder of forty-three students from a university in Guerrero State.

What led to the cartels’ growth?

Experts point to both domestic and international forces. In Mexico, the cartels use a portion of their vast profits to pay off judges, officers, and politicians. They also coerce officials into cooperating; assassinations of journalists and public servants by the cartels are relatively common. Dozens of politicians were killed ahead of the country’s midterm elections in 2021, with many of the deaths attributed to the cartels.

The cartels flourished during the seven decades that Mexico was ruled by a single party, the Institutional Revolutionary Party (PRI). Within this centralized political structure, drug trafficking groups cultivated a wide network of corrupt officials through which they were able to gain distribution rights, market access, and protection.

The PRI’s unbroken reign finally ended in 2000 with the election of President Vicente Fox of the conservative National Action Party (PAN). With new politicians in power, cartels ramped up violence against the government in an effort to reestablish their hold [PDF] on the state.

Cartels use a portion of their vast profits to pay off judges, officers, and politicians.

At the international level, Mexican cartels began to take on a much larger role in the late 1980s, after U.S. government agencies broke up Caribbean networks used by Colombian cartels to smuggle cocaine. Mexican gangs eventually shifted from being couriers for Colombian criminal organizations, including the infamous Cali and Medellín cartels, to being wholesalers. By 2007, Mexican cartels controlled an estimated 90 percent [PDF] of the cocaine entering the United States.

The U.S. government, despite waging a “war on drugs” and conducting other counternarcotics efforts abroad, has made little progress in reducing demand. In 2017, Americans spent $153 billion [PDF] on illegal drugs, including cocaine, heroin, marijuana, and methamphetamine. The growing use of synthetic opioids, including fentanyl, has contributed to a public health crisis

How are drugs smuggled into the United States?

Most of the illicit drugs entering the United States that are seized by authorities are discovered at official ports of entry, of which there are more than three hundred.

Traffickers employ various tactics to evade detection by U.S. authorities at the border. These include hiding or disguising drugs in vehicles or maritime vessels, smuggling them into the United States through underground tunnels, and flying them over border barriers using drones or other aircraft. After Mexican traffickers smuggle wholesale shipments of drugs into the United States, local groups and street gangs manage retail-level distribution in cities throughout the country.

What measures has Mexico taken to stem the drug trade?

Recent Mexican administrations have responded to cartels primarily by deploying security forces, often spurring more violence:

Felipe Calderón (2006–2012). President Calderón declared war on the cartels shortly after taking office. Over the course of his six-year term, he deployed tens of thousands of military personnel to supplement and, in many cases, replace local police forces he viewed as corrupt. With U.S. assistance, the Mexican military captured or killed twenty-five of the top thirty-seven drug kingpins in Mexico. The militarized crackdown was a centerpiece of Calderón’s tenure.

However, some critics say Calderón’s decapitation strategy created dozens of smaller, more violent drug gangs. Many also argue that Mexico’s military is ill-prepared to perform police functions. The government registered more than 120,000 homicides [PDF] over the course of Calderón’s term, nearly twice as many as during his predecessor’s time in office. (Experts estimate that between one-third and one-half of the homicides in Mexico are linked to cartels.)

Enrique Peña Nieto (2012–2018). Calderón’s successor said he would focus more on reducing violence against civilians and businesses than on removing the leaders of cartels. Still, President Peña Nieto relied heavily [PDF] on the military, in combination with the federal police, to battle the cartels. He also created a new national police force, or gendarmerie, of several thousand officers.

Homicides declined in the first years of Peña Nieto’s presidency. But 2015 saw an uptick, and by the end of his term, the number of homicides had risen to the highest level in modern Mexican history. Experts attribute this to the continued fallout from the kingpin strategy, territorial feuds, and cartel fragmentation.

Andrés Manuel López Obrador (2018–present). Shortly after taking office, President López Obrador, also known as AMLO, announced that his government would move away from militarized attempts to apprehend cartel leaders and instead focus on improving regional security cooperation and reducing homicide rates. His “hugs not bullets” approach seeks to address the socioeconomic drivers of organized crime by creating job opportunities. Since 2018, his administration has launched an anticorruption drive and disrupted cartel finances; it has also proposed decriminalizing all illegal drugs and offering amnesty to low-level cartel members.

Though AMLO has framed his strategy as a novel approach, some experts say his actions—including deploying a new military-led national guard to boost security—echo his predecessors’ tactics and are unsuccessful. Meanwhile, the homicide rate continues to hover around record levels.

What has been the toll on human rights?

Civil liberties groups, journalists, and foreign officials have criticized the Mexican government’s war with the cartels for years, accusing the military, police, and cartels of widespread human rights violations, including torture, extrajudicial killings, and forced disappearances. More than seventy-nine thousand people have disappeared since 2006, primarily at the hands of criminal organizations such as the cartels, though government forces also play a role. Local search efforts to find the missing and prosecute those responsible have often been stymied by cartel-related violence, government incompetence and corruption, and other factors.

One of the most chilling examples of these abuses occurred in the southern state of Guerrero in 2014, when forty-three student protesters were abducted and presumably killed, though remains of only three students have been definitively identified. The incident prompted mass demonstrations, with protesters demanding answers about the abductions and expressing their exhaustion with Mexico’s endemic corruption, violence, and other crime. Investigations into the students’ disappearances have purportedly found evidence that authorities, including the police and military, conspired with cartel members in the crimes; the government launched a new inquiry after the students’ families, human rights groups, and independent experts questioned the handling of the previous investigation. In August 2022, a judge ordered the former attorney general who oversaw the original investigation to stand trial on charges of forced disappearance, failure to report torture, and misconduct.

In recent years, vigilante groups known as autodefensas have sought to fill in where security forces have failed to protect communities from criminal groups. They have become a formidable force against the cartels in states including Guerrero and Michoacán. However, some vigilantes have committed rights abuses, including the recruitment of child fighters; allegedly maintained ties to cartels in exchange for weapons and protection; and even turned to organized crime themselves.

What assistance has the U.S. government provided?

The United States has cooperated with Mexico on security and counternarcotics to varying degrees over the past several decades. Recent efforts have centered on the Mérida Initiative; since Presidents George W. Bush and Calderón launched the partnership [PDF] in 2007, the United States has appropriated more than $3 billion for it. This assistance has gone toward purchases of military aircraft, surveillance software, and other equipment.

The initiative has evolved to reflect the priorities of national leaders. The Bush administration focused heavily on providing Mexico with security-related assistance, including counternarcotics and counterterrorism support. President Obama widened the scope of aid to target fundamental reforms to Mexico’s justice system and to develop crime-prevention programs at the community level, among other efforts, in what became known as “Mérida 2.0” [PDF].

President Donald Trump shifted U.S. priorities for Mérida to issues including border security and combating drug production and money laundering. In a highly controversial move in February 2019, Trump declared a national emergency at the U.S.-Mexico border and ordered the deployment of thousands of active-duty military troops there, citing an influx of illicit drugs, criminals, and undocumented immigrants. Mexico later deployed twenty-five thousand National Guard members to secure its borders, which some experts say increased violence and diminished the country’s cartel-fighting capacity.

A map of the U.S.-Mexico border, including barriers and ports of entry, showing that barriers have been constructed along most of the western part of the border.

The U.S.-Mexico relationship took a major hit in October 2020, when U.S. authorities arrested General Salvador Cienfuegos Zepeda, a former Mexican defense minister, in Los Angeles for drug trafficking and money laundering. Though the United States later dropped the charges and allowed Cienfuegos to return to Mexico, the Mexican government responded by restricting U.S. law enforcement agents’ power to operate in the country. 

President Biden inherited a tense security relationship with Mexico, with bilateral cooperation focused mostly on migration, COVID-19, and trade. In October 2021, Presidents Biden and López Obrador announced the creation of a bilateral framework to replace the Mérida Initiative that will seek to address both insecurity in Mexico and the opioid crisis in the United States. But just six months later, the AMLO administration drew outcry from U.S. officials by disbanding a DEA-trained anti-narcotics force that had worked closely with U.S. law enforcement for decades.

Recommended Resources

CFR’s Global Conflict Tracker looks at criminal violence in Mexico.

A Congressional Research Service report details the scope and activities [PDF] of Mexico’s drug trafficking groups.

In an interview with Insight Crime’s Katie Jones, University of Warwick Professor Benjamin T. Smith explains how his book The Dope unpacks misperceptions about Mexico’s drug trade

A 2021 report from the University of San Diego’s Justice in Mexico initiative details organized crime and violence in Mexico and offers policy recommendations [PDF].

The New Yorker joins Mexican mothers as they search for the bodies of their children, who have disappeared amid Mexico’s war on drugs.

The International Crisis Group’s Falko Ernst visualizes Mexico’s war against the cartels.

For media inquiries on this topic, please reach out to [email protected].

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