ISSN 2330-717X

Southwest Border Region: Illicit Drug Trade Between US And Mexico – Analysis


By Kristin M. Finklea, William J. Krouse and Marc R. Rosenblum

The nature of the conflict between the Mexican DTOs in Mexico has manifested itself, in part, as a struggle for control of the smuggling routes into the United States.9 Therefore, the prospects for spillover violence are most keenly anticipated in the Southwest border (SWB) region of the United States because the region represents the arrival zone for the vast majority of illicit drugs that are smuggled into the country. The size, geography, and climate of the SWB region have long presented unique challenges to law enforcement. The southern border with Mexico stretches nearly 2,000 miles in length, is sparsely populated in some areas, and is dotted with legitimate crossing points (ports of entry)—both large and small. The National Drug Threat Assessment, 2008, summarized the illicit drug threat scenario along the SWB in stark terms:

The Southwest Border Region is the most significant national-level storage, transportation, and transshipment area for illicit drug shipments that are destined for drug markets throughout the United States. The region is the principal arrival zone for most drugs smuggled into the Unites States; more illicit drugs are seized along the Southwest Border than in any other arrival zone. Mexican DTOs have developed sophisticated and expansive drug transportation networks extending from the Southwest Border to all regions of the United States. They smuggle significant quantities of illicit drugs through and between ports of entry (POEs) along the Southwest Border and store them in communities throughout the region. Most of the region’s principal metropolitan areas, including Dallas, El Paso, Houston, Los Angeles, Phoenix, San Antonio, and San Diego, are significant storage locations as well as regional and national distribution centers. Mexican DTOs and criminal groups transport drug shipments from these locations to destinations throughout the country.10

The most recent threat assessment indicates that the Mexican DTOs pose the greatest drug trafficking threat to the United States.11 Demand for illicit drugs in the United States partly drives this threat.

Demand for Drugs in the United States

The United States is the largest consumer of illegal drugs and sustains a multi-billion dollar market in illegal drugs.12 According to the Central Intelligence Agency, the United States is the largest consumer of Colombian-produced cocaine and heroin, as well as a large consumer of Mexican-produced heroin, marijuana, and methamphetamine.13

The latest National Household Survey on Drug Use and Health (NSDUH),14 in 2008, surveyed individuals aged 12 and older regarding their drug use during the previous month. Survey results indicated that an estimated 20.1 million individuals were current (past month) illegal drug users, representing 8% of this population. This percentage of users had remained relatively stable since 2002.15 Among these drug users, marijuana was the most commonly used drug, with an estimated 15.2 million users (6.1% of the population), followed by nonmedical use of prescription-type psychotherapeutic drugs (6.2 million users, or 2.5% of individuals). The survey also estimated that there were 1.9 million users of cocaine (0.7% of Americans), as well as 1.1 million users of hallucinogens (0.4% of the population)—of which 555,000 reported use of Ecstasy. Results also estimated 314,000 methamphetamine users.

Supply of Illegal Drugs from Mexico

Mexican DTOs are the major suppliers and key producers16 of most illegal drugs smuggled into the United States across the SWB. Moreover, Mexico is the major transit country for cocaine, according to the U.S. State Department; as much as 90% of the cocaine consumed in the United States comes through Mexico.17 According to the National Drug Intelligence Center’s (NDIC’s) 2010 National Drug Threat Assessment, cocaine availability was lower in 2007, 2008, and 2009 (relative to previous years) in certain areas of the United States for a number of reasons, including cocaine eradication, cocaine seizures, increased worldwide demand for cocaine, pressure on drug trafficking organizations in Mexico, inter-cartel violence, and border security.18 While cocaine availability decreased, the availability of heroin, marijuana, methamphetamine, and MDMA remained and even increased in some areas.19

In addition to controlling most of the wholesale cocaine distribution in the United States, Mexican DTOs also control more of the wholesale distribution of heroin methamphetamine and marijuana distribution than other major drug trafficking organizations in the United States. In 2008, there was an increase in heroin produced in Mexico and a subsequent increase in its availability in the United States. With respect to methamphetamine, there was a decline in seizures of Mexican-produced methamphetamine beginning in 2006 and continuing in 2007, in part because of Mexican import restrictions on precursor drugs beginning in 2005, as well as because some Mexican-based methamphetamine producers have more recently moved their laboratories into the United States.20 However, by 2008, the DTOs had circumvented the Mexican chemical control laws and were using non-ephedrine based production methods, including the phenyl-2-propanone(P2P) method.21 This has enabled a subsequent uptick in Mexican methamphetamine flow into the United States. Marijuana availability in the United States has also increased due to factors such as rising marijuana production in Mexico, increasing marijuana cultivation in the United States led by Mexican DTOs, and decreasing marijuana eradication in Mexico.22

The true quantity of drugs produced and transported by Mexican DTOs, however, is unknown. Available data provide insight into the quantity of drugs seized along the SWB, though this data cannot speak to the total amount of drugs produced and/or transported into the United States, nor does it provide information about the proportion of these drugs that are actually seized along the SWB. For instance, Table 1 illustrates federal seizures of illegal drugs along the SWB for calendar years (CY) 2005-2009. Total drug seizures generally increased during this time period, despite a decline in 2008. Specifically, cocaine seizures along the SWB decreased in 2007 and 2008 relative to previous years when cocaine seizures had been increasing, but seizures began to increase again in 2009, a year that was marked by an increase in all major illegal drug seizures except for seizures of MDMA. These data, however, do not provide insight into the total amount of drugs illegally produced and transported by the DTOs. Rather, this data reflect an unknown proportion of drugs that the Mexican DTOs are bringing into the United States through a variety of transportation modes.

The 2010 National Drug Threat Assessment indicates that Mexican DTOs, in addition to being the major supplier of illegal drugs being smuggled into the United States, have a strong presence within the United States.23

Mexican Drug Trafficking Organizations24

Mexican DTOs are transnational organized crime groups25 whose criminal activities center primarily around the drug trade. In general, organized crime groups attempt to fill particular illicit market niches. Specifically, DTOs respond to the societal demand for illegal drugs. Some experts have likened drug trafficking organizations to corporations or even small nation-states. They are influenced by factors such as geography, politics, economics, and culture.26 Geographically, for example, Mexican DTOs are situated between the world’s largest producer of cocaine (Colombia) and the world’s largest consumer of cocaine (United States), leading Mexico to be a natural drug transshipment route between the two countries.27 In addition, major Mexican criminal organizations focus primarily (though not exclusively) on drugs, because the drug trade has, to date, generally proven to be more economically lucrative than other illicit activities such as kidnapping and extortion.28

Mexican DTOs either (1) transport or (2) produce and transport drugs north across the United States-Mexico border.29 Figure 1 illustrates the drug trafficking routes within Mexico and at the United States-Mexico border. After being smuggled across the border by DTOs, the drugs are distributed and sold within the United States. The illicit proceeds may then be laundered or smuggled south across the border. The proceeds may also be used to purchase weapons in the United States that are then smuggled into Mexico.30 This leads to a general pattern of drugs flowing north across the border and money and guns flowing south.

Although Mexican DTOs have been active for some time, they have become more prominent since the decline of the powerful Colombian DTOs beginning in the 1980s.31 The NDIC estimates that Mexican DTOs maintain drug distribution networks—or supply drugs to distributors in at least 230 U.S. cities (as illustrated in Figure 2)—and annually transport multi-ton quantities of illicit drugs from Mexico into the United States using a variety of multi-modal transportation methods.32 Estimates are that these drugs generate between $18 billion and $39 billion in U.S. wholesale drug proceeds for the Colombian and Mexican DTOs annually.33

When conceptualizing Mexican drug trafficking organizations as businesses, policy makers may question the impact of possible drug trafficking-related violence spillover (into the United States) on the drug trafficking business—selling drugs in the U.S. black market. Although the effects of violence on businesses in the black market may not mirror those effects on business in the licit market, one way of examining this question may be to look at the impact that violence or violent crimes have on business in general. One recent study, for example, examined the impact of surges in violence on businesses in various industries in locations of varying crime rates.34 Results suggested that surges in violence had the most negative impact on those businesses that were service-related (e.g., retail and personal service industries) and located in typically low-crime areas.

Specifically, the impact on business was in terms of a reduction in the number of new businesses, a decrease in business expansions, and a lack of overall business growth. In order to generalize these findings from retail businesses to drug businesses, one underlying assumption must be that the locations for buying retail goods and personal services are the same as those for purchasing drugs. If these findings are generalizable to the drug trafficking business, this could suggest that any spillover in drug trafficking-related violence to the United States could adversely affect those service-related businesses (including drug trafficking businesses) in cities with relatively (pre-spillover) low crime rates. On the other hand, if violence affects businesses in the licit and illicit markets differently, these findings may not apply to potential effects of drug trafficking-related violence on drug trafficking business.

Already, there have been anecdotal predictions regarding the impact of violence on drug trafficking business; Douglas, AZ, police chief Alberto Melis has said that “spillover violence would be bad for business … and they’re [the drug traffickers] businessmen.”35 Further, the Drug Enforcement Administration (DEA) has expressed moderate confidence that there will not be a significant increase in spillover violence—at least in the short term—because “Mexican trafficking organizations understand that intentional targeting of U.S. persons or interests unrelated to the drug trade would likely undermine their own business interests.”36

Partnerships in the United States

The NDIC has indicated that in order to facilitate the distribution and sale of drugs in the United States, Mexican DTOs have formed relationships with U.S. street gangs, prison gangs, and outlaw motorcycle gangs.37 Although these gangs have historically been involved with retail-level drug distribution, their ties to the Mexican DTOs have allowed them to become increasingly involved at the wholesale level as well.38 These gangs facilitate the movement of illicit drugs to urban, suburban, and rural areas of the United States. Not only do these domestic gangs distribute sell the drugs, but they also aid in smuggling and enforcing the collection of drug proceeds.39 For example, Barrio Azteca is one of at least nine prominent U.S. prison gangs with ties to Mexican DTOs.40 Barrio Azteca primarily generates money from smuggling marijuana, heroin, and cocaine across the Southwest border for the DTOs—namely, the Juárez cartel—but they are also involved in other crimes, such as extortion, kidnapping, and alien smuggling.41


Like other organized crime groups, Mexican DTOs are profit-driven. While the primary goods trafficked by DTOs are drugs, some experts have noted that these organizations do generate income from other illegal activities, such as the smuggling42 of humans and weapons, counterfeiting and piracy, kidnapping for ransom, and extortion.43 If the DTOs are not able to generate income from the drugs—due to any number of reasons (increased Mexican or U.S. law enforcement, decreased drug supply, decreased drug demand, etc.)—they may increase their involvement in other money-generating illegal activities, such as kidnapping and home invasions. Take, for example, the number of drug trafficking-related kidnappings for ransom in Phoenix, AZ.44 In 2009, the NDIC reported 358 such incidents in 2007 and 357 in 2008 (through December 15, 2008), and indicated that nearly every incident was drug-related.45 These statistics were revised in the 2010 National Drug Threat Assessment, indicating that kidnappings in Phoenix reached 260 in 2007, 299 in 2008, and 267 in 2009.46 This decrease in the number of reported kidnappings for 2007 and 2008 is due to a reclassification of certain cases by the Phoenix Police Department. Further, the NDIC reports that kidnappings may be generally underreported because victims may fear retaliation for reporting or may expose their own involvement in drug trafficking. Still, Tucson, AZ, police have reported that although there has been an increase in kidnappings for ransom and home invasions, the suspects in the cases are ocal criminals—not active DTO members from Mexico.47 This disparity in reports indicates that while there may be an increase in certain illegal activities that may be tied to drug smuggling and trafficking, these illegal activities are not necessarily directly related to drug trafficking in general or to Mexican drug trafficking organizations in particular.



Kristin M. Finklea, Coordinator
Analyst in Domestic Security
William J. Krouse
Specialist in Domestic Security and Crime Policy
Marc R. Rosenblum
Specialist in Immigration Policy


This article is an edited portion of the larger June 9, 2011 Congressional Research Service report,” Southwest Border Violence: Issues in Identifying and Measuring Spillover Violence”


9 In addition, the drug related violence in Mexico is also resulting from a struggle between the drug trafficking organizations and the Mexican government attempting to crack down on the DTOs. For more information, see Scott Stewart and Alex Posey, Mexico: The War with the Cartels in 2009, Stratfor Global Intelligence, November 9, 2009,

10 U.S. Department of Justice, National Drug Intelligence Center, National Drug Threat Assessment, 2008, Product No. 2007-Q0317-003, October 2007, p. v, Hereinafter, NDTA, 2008.
11 U.S. Department of Justice, National Drug Intelligence Center, National Drug Threat Assessment 2010, Product No. 2010-Q0317-001, February 2010, Hereinafter, NDTA, 2010.
12 Oriana Zill and Lowell Bergman, “Do the Math: Why the Illegal Drug Business is Thriving,” PBS Frontline,
13 U.S. Central Intelligence Agency, World Fact Book, available at factbook/index.html.
14 NSDUH is an annual survey of approximately 67,500 people, including residents of households, non- institutionalized group quarters, and civilians living on military bases. The survey is administered by the Substance Abuse and Mental Health Services Administration of the U.S. Department of Health and Human Services and is available at
15 According to the NSDUH, within the period 2002 – 2008, the annual percentage of illicit drug users in the 12 and older age group ranged from 7.9% to 8.3%.

16 Mexican DTOs distribute cocaine (produced primarily in Colombia), and they produce as well as distribute heroin, methamphetamine, and marijuana.
17 U.S. Department of State, Bureau for International Narcotics and Law Enforcement Affairs, 2009 International Narcotics Control Strategy Report (INCSR), vol. 1, March 2009, p. 414.
18 NDTA, 2010. 19 Ibid., p. 27.
20 U.S. Department of Justice, National Drug Intelligence Center, National Drug Threat Assessment 2009, Product No. 2008-Q0317-005, December 2008, p.9, Hereinafter, NDTA, 2009.
21 NDTA, 2010, p. 34. 22 Ibid., p. 36.

23 Ibid, p. 9.
24 The terms drug trafficking organization (DTO) and drug cartel are terms often used interchangeably. Cartel is one of the dominant terms used colloquially and in the press, but some experts disagree with using this term because “cartel” often refers to price-setting groups and because it is not clear that the Mexican drug trafficking organizations are setting illicit drug prices. For the purpose of consistency, this report uses the term drug trafficking organization. For more information on the Mexican DTOs, see archived CRS Report RL34215, Mexico’s Drug Cartels, by Colleen W. Cook. For information on the current violence between the DTOs in Mexico, see CRS Report R41576, Mexico’ s Drug Trafficking Organizations: Source and Scope of the Rising Violence, by June S. Beittel.
25 For more information on organized crime in the United States, see CRS Report R40525, Organized Crime in the United States: Trends and Issues for Congress, by Kristin M. Finklea; and CRS Report R41547, Organized Crime: An Evolving Challenge for U.S. Law Enforcement, by Jerome P. Bjelopera and Kristin M. Finklea.
26 Stratfor Global Intelligence, Mexican Drug Cartels: The Net Assessment, March 9, 2008, podcast/mexican_drug_cartels_net_assessment.

27 Stratfor Global Intelligence, Organized Crime in Mexico, March 11, 2008, organized_crime_mexico.
28 Ibid. Refer to the section in the report, “Activities,” for more information on other illicit activities engaged in by the drug trafficking organizations.
29 As mentioned, Mexican DTOs distribute cocaine (produced in Colombia, Venezuela, and Brazil), and they produce as well as distribute heroin, methamphetamine, and marijuana.
30 For more information on gun trafficking on the Southwest border, see CRS Report R40733, Gun Trafficking and the Southwest Border, by Vivian S. Chu and William J. Krouse.

31 Stratfor Global Intelligence, Organized Crime in Mexico, March 11, 2008, organized_crime_mexico. See also archived CRS Report RL34215, Mexico’ s Drug Cartels, by Colleen W. Cook.
32 NDTA, 2009., p. 45.
33 NDTA, 2009., p. 49. According to ONDCP data, the trafficking and distribution of cocaine generates about $3.9 billion, marijuana generates about $8.5 billion, and methamphetamine generates about $1 billion. Jane’s, Security, Mexico, February 20, 2009.

34 Robert T. Greenbaum and George E. Tita, “The Impact of Violence Surges on Neighbourhood Business Activity,” Urban Studies, vol. 41, no. 13 (December 2004), pp. 2495-2514.
35 Brady McCombs and Tim Steller, “Drug Violence Spillover More Hype Than Reality: Southern Arizona Lawmen Discount Threat of Cartel Warfare Crossing Border,” Arizona Daily Star, April 26, 2009, Tucson Region.
36 Drug Enforcement Administration, Statement of Joseph M. Arabit Special Agent in Charge, El Paso Division, Regarding “Violence Along the Southwest Border” Before the House Appropriations Committee, Subcommittee on Commerce, Justice, Science and Related Agencies, March 24, 2009,
37 NDTA, 2009, p. 46.
38 Wholesale refers to the sale of goods to retailers for resale to consumers rather than selling goods directly to consumers. Retailers, on the other hand, sell goods directly to consumers. Wholesalers tend to sell larger quantities of goods to retailers, who then sell smaller quantities to consumers.

39 NDTA, 2009., pp. 43-46. See also, National Gang Intelligence Center and National Drug Intelligence Center, National Gang Threat Assessment, 2009, Product No. 2009-M0335-001, January 2009, publications/ngta2009.pdf.
40    Fred Burton and Ben West, The Barrio Azteca Trial and the Prison Gang-Cartel Interface, Stratfor Global Intelligence, November 19, 2008, 20081119_barrio_azteca_trial_and_prison_gang_cartel_interface.
41 For more information, see Tom Diaz, “Barrio Azteca—Border Boys Linked to Mexican Drug Trafficking Organizations—Part Three,” April 17, 2009, azteca%E2%80%93border-bad-boys-linked-to-mexican-drug-trafficking-organizations-%E2%80%94-part-three/. See also the U.S. Department of Justice website at
42 While drug trafficking organizations may not be directly involved in alien or gun smuggling, they may tax the smugglers who wish to use the established drug trafficking routes. Further, the NDIC has indicated that drug trafficking organizations may engage in violent confrontations with the smuggling organizations, as the drug traffickers fear that the smugglers’ use of their routes may lead to the traffickers’ apprehension. See National Drug Intelligence Center, Office of National Drug Control Policy, Arizona High Intensity Drug Trafficking Area: Drug Market Analysis 2009, Product No. 2009-R0813-002, March 2009, p.14,
43 Jane’s, Security, Mexico, February 20, 2009. Also, Stratfor Global Intelligence, Mexican Drug Cartels: The Net Assessment, March 9, 2008,
44 Sam Quinones, “Phoenix, Kidnap-For-Ransom Capital,” Los Angeles Times, February 12, 2009. See also, National Drug Intelligence Center, Office of National Drug Control Policy, Arizona High Intensity Drug Trafficking Area: Drug Market Analysis 2009, Product No. 2009-R0813-002, March 2009, 32762p.pdf.
45 Ibid., p. 18. 46 NDTA, 2010, pp. 15-16

46 NDTA, 2010, pp. 15-16.

47 Brady McCombs and Tim Steller, “Drug violence spillover more hype than reality: Southern Arizona lawmen discount threat of cartel warfare crossing border,” Arizona Daily Star, April 26, 2009, Tucson Region.

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