According to a recent book, the United States sells more weapons to Mexico than any other country in the world. Guadalupe Correa-Cabrera (2017) "Los Zetas Inc:

According to a recent book, the United States sells more weapons to Mexico than any other country in the world. Guadalupe Correa-Cabrera (2017) "Los Zetas Inc: Criminal Corporations, Energy, and Civil War in Mexico", p. 228. https://www.amazon.com/Los-Zetas-Inc-Criminal-Corporations/dp/1477312757/ref=sr_1_2?crid=30ERQC7TX2DO1&dchild=1&keywords=los+zetas+inc&qid=1605832678&s=books&sprefix=los+zetas+inc%2Cstripbooks%2C190&sr=1-2 https://www.amazon.com/Los-Zetas-Inc-Criminal-Corporations/d...