Last week a USD Trans-Border Institute study reported that, on average, 252,000 guns are smuggled from the U.S. into Mexico – significantly more than previously thought. The methodology, while not exact (the calculations were based on a percentage of total gun sales in the border region), seems plausible and confirms long-running suspicions about the magnitude of the problem. While I am somewhat skeptical that simply reducing the flow of weapons into Mexico will reduce levels of violence–the weapons smuggling is demand-driven, not supply-driven–it is important to acknowledge that the the extent of U.S. complicity in the violence goes beyond demand for drugs.
It is also worth noting that, from a historical perspective, there is some precedent for controlling cross-border arms flows. During the Mexican Revolution, the Wilson administration strategically used access to the U.S. arms market to tip the balance of power toward the eventually-victorious Carranza faction. But where those decisions bordered on interventionist, current policy seems to violate a moral imperative to, in the very least, do no harm.