Key Takeaways:
- A September GAO report found that U.S. agencies track firearms seizures bound for Mexico but lack adequate performance measures to assess whether trafficking is being effectively disrupted, reinforcing Mexican complaints that most seized weapons are of U.S. origin.
- Washington is expanding counter-narcotics cooperation through access arrangements such as Cooperative Security Locations and temporary deployments in countries including El Salvador, Panama, and Ecuador, while distinguishing these from permanent bases amid local political sensitivities.
- The article argues that military operations and regional access should be matched by sustained progress against U.S.-based arms-trafficking networks, clearer oversight of force-use rules, and transparent agreements so that deeper American involvement rests on demonstrable results closer to home.
Washington is extending its military reach through security partnerships. Its response to the weapons flowing south deserves the same scrutiny.
Washington’s expanding campaign against Latin America’s drug networks has an unresolved problem closer to home: how effectively is the United States stopping the weapons that help those networks fight?
A report published by the US Government Accountability Office on 28 September gives that question fresh urgency. Federal agencies record seizures and conduct investigations into firearms trafficking to Mexico, but lack adequate measures to determine whether their efforts are meeting their objectives. The congressional watchdog identified shortcomings across the departments of Homeland Security and State, and the Bureau of Alcohol, Tobacco, Firearms and Explosives, or ATF.
That finding lends weight to a complaint Mexico has repeatedly brought to Washington. On 23 February, Mexican Defence Secretary Ricardo Trevilla Trejo said that 80% of the 23,000 weapons seized during President Claudia Sheinbaum’s administration were of US origin. His statement concerned the seizures reported at that point in the administration; it was not a census of every weapon held by organised crime.
The issue reaches beyond a dispute over border enforcement. As the United States develops military partnerships and operational access across the region, its credibility also depends on what it can demonstrate about the arms moving out of its own territory. A strategy that measures success abroad through raids and deployments needs an equally demanding test for the supply networks at home.
US data independently establish a substantial American connection, although they measure a different sample. ATF figures for firearms recovered in Mexico in 2024 and submitted for tracing classified 18,249 of 25,884 weapons, or 70.5%, as US-sourced. That category includes firearms manufactured in the United States and those legally imported into it.
The distinction matters. A weapon’s country of manufacture, its first commercial market and the route by which it reaches a criminal organisation can differ. ATF also warns that traced firearms are not a random sample representative of all weapons used by criminals. Its percentage should therefore neither be substituted for Trevilla’s figure nor presented as the American share of the entire cartel arsenal.
Nor does an American connection, by itself, establish that the US government deliberately supplied a criminal group. Establishing responsibility requires evidence about the sale, diversion or trafficking of particular weapons. The policy question is whether authorities are identifying and disrupting those routes with sufficient consistency.
Washington can point to enforcement. On 18 February, the Justice Department announced that ATF had seized 4,359 firearms and 648,975 rounds of ammunition bound for Mexico since 20 January 2025. Those figures demonstrate action against the trade, although they do not establish what proportion of the overall flow was intercepted.
The GAO’s more recent findings expose the measurement problem. It found that ATF had discontinued performance measures established in fiscal 2023, while Homeland Security had not established the goals and measures needed to assess its efforts. Counting seizures records activity. Assessing whether traffickers find it harder to obtain and replace weapons requires a more demanding evaluation.
Mexico has also encountered legal limits in pursuing the manufacturers. In June 2025, the US Supreme Court unanimously held that its complaint against American gunmakers did not plausibly allege the aiding and abetting necessary to overcome the Protection of Lawful Commerce in Arms Act. The ruling concerned the legal sufficiency of Mexico’s case. It did not resolve the wider policy problem of firearms trafficking across the border.
These limits on accountability at the supply end deserve attention alongside the widening scope of the military response. To understand that expansion, however, it is necessary to distinguish a permanent foreign base from access to a host country’s facilities, a temporary deployment or a joint operation. Each gives Washington different capabilities and creates different obligations for the government receiving it.
The access model has a long history. US Southern Command identifies Cooperative Security Locations at Comalapa in El Salvador and in Aruba–Curaçao. They allow American and partner aircraft to use existing airfields for operations against transnational organised crime. SOUTHCOM explicitly distinguishes these arrangements from bases. The US Navy describes Comalapa’s role as providing logistical, infrastructure and operational support to deployed aviation units conducting counter-narcotics missions.
Such arrangements can still have substantial strategic value. Access to an airfield, maintenance support and permissions for recurring operations can sustain a military presence without a large American-owned installation. The practical questions concern what forces are authorised to do, how frequently they deploy and who can limit or terminate their activities.
Panama illustrates the political sensitivity. An April 2025 US–Panama joint statement envisaged expanded cooperation and a memorandum supporting activities at joint-use locations. Panama’s Ministry of Public Security subsequently said the agreement covered technical cooperation against drug trafficking, terrorism and transnational crime, while explicitly ruling out the establishment of foreign military bases.
The strategic purpose also extended beyond narcotics. During his visit, US Defence Secretary Pete Hegseth linked closer cooperation to securing the Panama Canal and countering Chinese influence. Panama rejected Washington’s assertion that China controlled the waterway. Counter-crime cooperation was therefore developing within a broader argument over strategic infrastructure and external influence.
Ecuador presents an even clearer test of the boundary between rejecting foreign bases and accepting foreign military activity. In the November 2025 referendum, voters rejected a proposal to permit foreign military bases, dealing a setback to President Daniel Noboa, who had supported the change as a means of strengthening the fight against organised crime.
Yet on 17 December, the US embassy announced a temporary deployment of American Air Force personnel to Manta for cooperation with Ecuador’s air force. The embassy described it as a short-term effort within a longer-term bilateral security strategy, operating under existing agreements and Ecuadorian law. Manta had previously hosted a US forward operating presence that ended in 2009.
Cooperation subsequently moved into announced operations. On 3 March 2026, SOUTHCOM said Ecuadorian and US military forces had launched operations against designated terrorist organisations in Ecuador. The announcement confirmed operational cooperation; it did not establish the creation of a permanent American base.
The sequence raises a legitimate question about democratic oversight. Rejecting foreign basing does not necessarily prohibit every form of military cooperation. But where temporary deployments develop into recurring operations, citizens need enough information to judge whether the government is respecting the limits they endorsed. The duration of access and the missions it permits matter as much as the terminology used to describe it.
By September, Washington was publicly describing a more collaborative approach to operations in regional waters. During a visit to Quito on 9 September, Secretary of State Marco Rubio emphasised working with allied governments and their laws, while retaining the option of destroying vessels. The Associated Press reported a shift towards negotiated cooperation following the campaign of unilateral lethal strikes that began a year earlier.
Cooperation does not settle the controversy over the use of force. Human Rights Watch has characterised the maritime strike campaign as unlawful and challenged the administration’s claim that it is engaged in an armed conflict with drug-trafficking organisations. SOUTHCOM, responding to reporting on the destruction of Ecuadorian vessels in September, maintained that its operations complied with US and international law.
Partner governments consequently face questions that extend beyond permission to use a runway. What evidence supports targeting a vessel? When can its occupants be detained and prosecuted? Who investigates an alleged mistake? Expanding operational cooperation without credible answers risks weakening the institutions that counter-narcotics assistance is supposed to support.
The wider geopolitical ambition is increasingly explicit. Addressing regional defence ministers in Cusco in July, Pentagon policy chief Elbridge Colby presented the administration’s revived Monroe Doctrine as a means of strengthening partner countries and protecting American security. His remarks connected regional defence with drugs, migration and the protection of critical assets from outside actors.
Taken together, the arrangements suggest that counter-narcotics cooperation is also helping Washington secure access and shape regional security priorities. That is an inference from their operational and political purposes, not evidence that every deployment is a covert base or that drug trafficking is merely an invented pretext. Partner governments have their own security objectives, and the conditions under which they accept assistance deserve close examination.
A more credible approach would give arms-trafficking investigations and financial prosecutions sustained attention alongside military operations. US agencies should be able to explain how they assess disruption of supply networks, rather than treating each seizure as sufficient evidence of progress. Governments hosting American forces should publish the scope and duration of access agreements and provide a clear process for investigating harm.
Mexico’s responsibility for confronting organised crime remains substantial. So does the American responsibility to address the weapons leaving its market. Washington’s expanding freedom to operate in Latin America should be accompanied by demonstrable progress against the traffickers operating closer to home. Showing that it has made the cartels harder to arm would give Washington a stronger basis for asking its neighbours to accept a deeper American military role.
