US-Mexico Security Cooperation After the Bicentennial Framework

WASHINGTON, Nov. 6, 2026 — The United States and Mexico share a border of nearly 2,000 miles, and Mexico was the top U.S. trading partner in goods and services combined in 2025, the Congressional Research Service reported on Sept. 23. The same report describes a security relationship that has been rebuilt, tested and reorganized several times, most recently through a bilateral Security Implementation Group that U.S. and Mexican officials announced during Secretary of State Marco Rubio’s visit to Mexico in September 2025.

The older organizing document was the U.S.-Mexico Bicentennial Framework for Security, Public Health, and Safe Communities, launched in October 2021. A separate CRS brief, updated Dec. 11, 2025, traces that framework to a longer record of aid: Congress appropriated some $3.6 billion for U.S.-Mexico security cooperation from fiscal 2008 through fiscal 2023, beginning with the Merida Initiative in 2008. CRS writes that, under President Claudia Sheinbaum, who took office in October 2024, Mexico has cooperated with Washington on counternarcotics while opposing unilateral U.S. military action on Mexican territory.

From a framework to an implementation group

CRS records that the September 2025 joint statement listed a broad set of aims, including combating arms trafficking, a long-standing Mexican priority, and restated principles of “respect for sovereignty” and “shared and differentiated responsibility.” The statement, CRS notes, did not specify methods for measuring progress.

Officials convened a fourth meeting of the Security Implementation Group on June 12, 2026, and again said cooperation would continue with “full respect for each country’s sovereignty,” according to CRS, citing a Mexican government release. The report places that language in the context of Mexican sensitivity to U.S. activity inside Mexico, including public controversy over the deaths of two CIA officers in Chihuahua and later, unconfirmed press claims of a CIA role in a lethal operation. CRS records that the Mexican government and the CIA denied those claims.

The State Department designated eight Mexican drug cartels as foreign terrorist organizations, six in February 2025 and two more in July 2026, CRS reports. President Sheinbaum has criticized some U.S. visa revocations, sanctions and indictments of Mexican officials as interference, while also urging corrupt politicians in her party to resign, according to the same report.

Mexico is not a member of the Americas Counter Cartel Coalition that defense officials from the United States and partner governments launched in March 2026, CRS says. The report cites U.S. assessments that describe Mexico as the primary source country for U.S.-bound synthetic drugs, including fentanyl.

Aid, Congress and the limits of the relationship

Most U.S. security assistance to Mexico has flowed through the State Department’s International Narcotics Control and Law Enforcement account. CRS says that funding averaged $100 million a year from fiscal 2015 through fiscal 2021 before falling to $64 million in fiscal 2022 and $48 million in fiscal 2023 and 2024. The second Trump Administration continued that account and requested $90 million for Mexico in its fiscal 2027 budget request, CRS reports, while ending Economic Support Fund programs for human rights and rule of law after broader foreign-aid cuts in 2025.

Congress has added reporting and conditions. The fiscal 2026 National Defense Authorization Act required reports and plans on joint training, fentanyl trafficking and strategies for countering transnational criminal organizations in Mexico, CRS says. The fiscal 2026 national-security appropriations act withheld non-fentanyl-related aid until the secretary of state certifies Mexico is delivering water owed under a 1944 treaty, and withheld 30 percent of International Narcotics Control funds until Mexico meets specified antidrug conditions.

CRS also records cooperation that is easier to measure in public: as of January 2026, Mexico had transferred 92 drug traffickers into U.S. custody, and Mexican financial intelligence has supported U.S. Treasury sanctions. Those figures sit beside a political constraint the report states plainly. Sheinbaum has worked with U.S. agencies on intelligence and operations, CRS writes, but has opposed overt U.S. military operations inside Mexico. Peter’s World tracks this relationship on the Mexico hub and the United States country page. Related reporting includes the Americas counter-cartel coalition plan and a U.S.-Guyana defense partnership that sits in the same regional security debate.

Sources

• Congressional Research Service: Mexico: Background and U.S. Relations (R48859)
• Congressional Research Service: Evolution of U.S.-Mexico Security Cooperation (IF10578)

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