US-Mexico security cooperation centers on intelligence sharing and Mexican-led raids against groups like the CJNG, including the recent DEA-supported capture of leader “R2” in Jalisco and prior operations targeting figures such as El Mencho. The Trump administration has designated major cartels as foreign terrorist organizations, authorized maritime interdictions, formed a new counter-cartel task force under Northern Command, and pressed Mexico via diplomatic memos for US personnel to join ground actions or strikes inside the country. Mexican President Sheinbaum has repeatedly rejected any foreign military presence on national soil, citing sovereignty and existing laws that limit such participation. Trader assessments reflect this diplomatic standoff, with bilateral extraditions and border deployments continuing while direct US ground involvement remains the unresolved variable before the December 31 deadline.