Short version: the U.S. military can help — but it can’t simply “beat” the cartels like an army beats an army. Real progress requires a precise mix of legal restraint, intelligence-driven targeting, law-enforcement action, international cooperation, financial pressure, and domestic demand-reduction. Anything else either fails or blows up into a regional crisis. Here’s the playbook, the limits, the risks, and what would actually move the needle.

The legal and practical limits

• Active-duty troops can’t do regular policing inside the U.S. The Posse Comitatus framework restricts direct law-enforcement roles for the Department of Defense; military forces generally provide support (surveillance, logistics, engineering, intel) rather than arrests. National Guard under state control can fill some gaps, but that’s limited and political. www.csis.org
• Sovereignty matters. Large-scale kinetic action inside Mexico would violate Mexican sovereignty unless Mexico invites it — and even then it’s messy. Historically the U.S. has worked with partner governments and regional task forces instead of unilateral invasions. www.southcom.mil

What the military can do effectively

• Interdiction at sea and in transit corridors. Joint operations (Coast Guard + Navy + partner navies) have proven useful at interrupting maritime shipments and interdiction of unusual platforms (go-fast boats, semi-subs). These are classic DOD/coast guard missions where military assets add value. www.southcom.mil
• Intelligence, surveillance, reconnaissance (ISR). High-end airborne and space ISR, signals intelligence, and targeting analysis can map cartel networks for DEA/host-nation prosecutors to act on. Military sensors + law enforcement leads to arrests and seizures rather than artillery. www.dea.gov
• Training and capacity building. Helping partner militaries, coast guards, and police build forensics, border control, financial investigations, forensic labs, and prosecutors’ capacity reduces impunity. This is slower but lasting. www.dea.gov
• Counter-threat finance & sanctions. Treasury/OFAC actions and coordinated law-enforcement financial operations can choke cartel cashflows — something military intel can support by identifying assets and routes. home.treasury.gov

What doesn’t work (and why)

• Purely military campaigns to “destroy” cartels: Cartels are criminal economies, not conventional armies. Even heavy strikes that remove leaders often just produce fragmentation, more violence, and new smuggling routes. Analysts warn militarization risks strategic overreach and human-rights problems. www.csis.org
• Overreliance on interdiction. Stopping shipments matters but is whack-a-mole unless you also attack money laundering, weapons supply, corruption, and the demand inside the U.S. Seizures without prosecutions and asset forfeiture limits are short-term wins. www.dea.gov

Risks and second-order effects

• Escalation & regional destabilization. Heavy-handed military moves risk clashes with host states, spur violence against civilians, or invite outside actors to exploit chaos. Experts emphasize careful objectives and exit strategies. ctc.westpoint.edu
• Political/legal backlash at home. Using the military for long domestic law-enforcement tasks raises constitutional and civil-liberties questions. www.csis.org

A realistic strategy that could work

• 1) Clarify objective: Is the goal fewer overdose deaths in the U.S.? Fewer violent homicides in Mexico? Disrupting transnational networks? Each goal needs different tools. (Clarity prevents policy theatre.)
• 2) Law-enforcement lead, military support: Keep DEA, FBI, and host-nation prosecutors in the driver’s seat; use DOD for ISR, interdiction at sea, logistics, and partner-capacity building. www.dea.gov
• 3) Attack the business model: Aggressively pursue money laundering, sanctions, and illicit finance; follow the cash into front companies and real estate. Treasury + DOJ + international partners are crucial. home.treasury.gov
• 4) Fix the supply of weapons & precursor chemicals: Tighten enforcement on U.S. gun trafficking to Mexico and international precursor flows; partner with suppliers’ countries to cut inputs.
• 5) Demand reduction at home: Expand evidence-based addiction treatment, harm-reduction, and prevention — reduce the market that funds the cartels. (This is the single most under-funded lever.)
• 6) Anti-corruption & rule-of-law programs: Invest in prosecutorial independence, witness protection, and transparency in partner states to prevent cartels from co-opting state institutions.
• 7) Measured, multilateral pressure: Sanctions, extraditions, diplomatic pressure, and intelligence sharing with regional partners reduce sanctuaries and safe havens. www.dea.gov

Bottom line (for people who like blunt metaphors)

Think of the cartels as a globalized criminal corporation, not an invading army. You don’t beat a corporation with tanks; you degrade its logistics, seize its cash, jail its executives, cut off its suppliers, and shrink its market. The military is a powerful toolbox — but mostly as support for law enforcement and partner-capacity building, not as the main prosecutor.If you want, I can:

• sketch a one-page policy memo the President could use (objectives, authorities, risks, metrics), or
• map out the specific legal authorities (Posse Comitatus, 10 U.S.C. sections, counter-drug authorities) and how they limit/permit action, or
• build a short timeline of past U.S. military-law enforcement collaborative ops (Operation Martillo, recent DEA surges) and what they actually achieved. Which of those digs deeper the way you want — memo, legal map, or historical case study?