Growing tensions between Mexico and the United States are exposing deep fractures in their long-standing security partnership. Amid rising cartel-related violence and a worsening fentanyl crisis, which prompted the January declaration of national emergency along the southern border, the Trump administration is reportedly mulling a controversial move: unilateral drone strikes on Mexican territory. While framed as a legitimate response to national security concerns, the potential military action risks sparking a diplomatic row and testing the limits of bilateral cooperation.

As Reuters and NBC News have reported, senior officials in Washington, including at the Department of Defense and CIA, are actively weighing the use of lethal force against Mexican drug cartels. Surveillance flights authorised by Mexico are currently gathering intelligence on potential targets such as cartel warehouses and operatives. Yet the real rupture lies not in the intelligence sharing, but in the suggestion that the US could act alone, bypassing Mexican consent if necessary.

President Claudia Sheinbaum has been unequivocal in her response. “The people of Mexico will not, under any circumstances, accept intervention, interference, or any other act from abroad,” she said at a press conference, warning that such action would neither solve the drug crisis nor respect Mexico’s sovereignty. Her administration has even proposed a constitutional reform to reinforce national protections against foreign military interference.

"That wouldn't solve anything. The solution is to be permanently addressing the causes and making arrests, which have to do with intelligence and investigation, coordination, and zero impunity," Sheinbaum added.

According to CNN, the CIA is conducting internal assessments of the legal feasibility and strategic risks of covert operations, including the use of lethal force. These deliberations include concerns over blowback from cartels and the possible diplomatic fallout, especially if civilians or US interests become collateral damage. A former CIA official noted the agency would “want to verify two or three times” before executing any such operation.

While the US argues that designating cartels as terrorist organisations could legally justify more aggressive countermeasures, international law experts caution that unilateral military strikes would likely breach sovereignty and violate key agreements. Critics also point to the historical precedent of joint US-Mexico efforts, such as the “kingpin strategy” under President Calderón, which achieved limited success but intensified cartel fragmentation and violence.

Ultimately, whether this aggressive posture is mere sabre-rattling or a prelude to escalation remains unclear. But any action taken without Mexican approval could derail one of the region’s most critical diplomatic relationships. As former Mexican ambassador Arturo Sarukhán put it, such a move “would represent a violation of international law and an act of war.”