Arizona Guns Fuel Mexico's Cartel War as Sinaloa Conflict Rages On
Mexican military officers presented confiscated firearms to Marina del Pilar, the governor of Baja California, during an inspection in Tijuana on 17 March 2026. This demonstration underscored a critical issue: Arizona has surpassed Texas to become the leading source of guns seized in Mexico and traced to recent US purchases, intensifying the bloody conflict within the Sinaloa cartel.
Escalating Violence and US Firearms Flow
When war erupted within the Sinaloa cartel, one of Mexico's most powerful criminal organisations, many hoped it would be short-lived. However, over a year and a half later, the violence persists, driven by a steady influx of firearms from the United States. According to recent data, 62% of guns seized in Mexico in 2024 and traced to a US purchase made less than a year earlier originated from Arizona, a key indicator that these weapons were bought specifically for trafficking purposes.
Arizona Attorney General Kris Mayes emphasised the severity of the problem, stating, "We have an enormous problem with gun trafficking by the Mexican drug cartels from Arizona down into Mexico. There is no doubt in my mind about that." Mexican authorities recover firearms and submit serial numbers for tracing by US counterparts, revealing this alarming trend.
Cartel Infighting and Rising Death Toll
The conflict ignited after Ismael "El Mayo" Zambada, co-founder of the Sinaloa cartel with Joaquín "El Chapo" Guzmán, was detained in July 2024 along with one of Guzmán's sons. Zambada accused Guzmán's son of betrayal, leading to a faction led by Zambada's son waging war against another faction controlled by El Chapo's remaining free sons in Mexico.
Miguel Calderón, coordinator of Sinaloa's state council on public security, noted in December 2024, "We don't know what their inventory of guns, ammunition, men and vehicles is. I imagine they're pulling together everything they have. This is the mother of all battles." The violence has resulted in approximately 5,000 people dead or missing, with no signs of the factions depleting their firearm supplies.
Since the war began, Mexican security forces have seized nearly 5,000 firearms in Sinaloa alone, accounting for roughly 20% of all guns confiscated nationwide during that period. Mexico's strict gun laws, with only two legal gun shops operated by the military, force criminal groups to seek firepower abroad, primarily from the US.
Shift in Trafficking Patterns and Legal Challenges
John Lindsay-Poland, coordinator of the Stop US Arms to Mexico project, highlighted that traced guns from 2024 with a short "time to crime" are heavily concentrated in Phoenix's county, with others coming from Tucson and Texas. This shift is reflected in Sonora, the Mexican state bordering Arizona, recording the second-highest number of gun seizures in 2025 after Sinaloa.
"This is a change, because for many years, Tamaulipas on the Gulf coast was by far the state with most guns recovered," said Lindsay-Poland. "And Texas was also dominant in the number of guns sold and then found in Mexico with a short time to crime." Arizona, like Texas, has relatively lax firearm purchase laws, making it a hotspot for cartel associates recruiting American "straw purchasers" who buy guns for commissions before trafficking them south.
Attorney General Mayes recently announced the indictment of a gun-trafficking ring involving 20 people who purchased over 330 firearms, many ending up in Mexico, but she suspects "this is just the tip of the iceberg." Her office reports that markups for trafficked guns, especially rifles like AR-15s and AK-47s, have spiked in Mexico, increasing commissions for straw purchasers in Arizona, likely due to cartel infighting demand.
Government Responses and Border Dynamics
The Mexican government has filed an ongoing lawsuit against five Arizona gun shops accused of facilitating gun trafficking. Additionally, Mexican President Claudia Sheinbaum has urged former US President Donald Trump to help stem the flow of illegal firearms into Mexico. Despite these efforts, the border between Arizona and Sonora remains a focal point for trafficking, also serving as the primary route for fentanyl seizures entering the US.
Mayes described the dual crisis: "Arizona is the fentanyl funnel for the rest of the [US], and it's also where firearms are being funnelled down into Mexico. So this is a twin problem." As the Sinaloa cartel war continues, the influx of Arizona-sourced weapons exacerbates violence, challenging both nations' security and policy efforts.
