Who cares where the guns are coming from, what really matters is where the money is coming from. Cut off the money flow, and you'll cut them off at the knees.
Although correct that is a very simplistic statement. You are overlooking the fact (common knowledge in the intelligence community) that our own civilian intelligence agency has used drug smuggling into our own country to fund their "Black Ops." It's like the FBI will ignore murder and other major crimes perpetrated by "informants" in order to build cases on targeted people. They often flub up as they did with Senator Stevens of Alaska, messed up the investigation so bad the Justice Department had to throw the "conviction" and case out before the appeal was heard. That was a Politically motivated investigation to get a super majority in the Senate which they now have thanks to the selfserving Senator Specter (aka Senator Spectical).
You can call me a liar or a fabricator if you like because I know you won't find any direct evidence, but in the Military I was in the Intelligence branch and I was a Police Officer after that. I know that information from 1st hand observation but I can't prove it.
The reason the CIA took out Noriega was that he wanted too much of a cut and was trying to take over the entire drug operation that the CIA was using. Their problem was that while they concentrated on Noriega the Columbia Drug Cartels got the upper hand and took over direct control of the "business." So the CIA changed it's drug smuggling routes from using Panama, Graneda, and other Caribbean Countries and started using Mexico and Puebla Cities. Now the Mexican Drug Cartels are trying to take over just like in Columbia, there are ties between them.
You want to get an earful, ask a Vietnam vet about the CIA and it's air fleet called Air America. I was actually riding in a DC4 "passenger" plane that dropped bombs over North Vietnam on a flight from Formosa to Saigon. Only US Government "civilians" and US Military personel were about the aircraft.
Again I can't prove but I was there. The CIA was actually transporting munitions into Loas and Cambodia disguised as medical supplies. Unfortunately they had one of the trucks go off the road and into a Calong (canal) in Ramasan, Thailand while I was the MP Provost Sargent there, so I know that one 1st hand too, but again I can't prove it.