As EFE reports, the two leaders signed an extradition treaty, which was originally announced last month, as well as an agreement to deepen judicial and police cooperation with regard to organized crime. Santos, who was elected last year, and Calderon, who leaves office next year, also finalized a number of economic accords.

The leaders said that such cooperation is key to a more effective approach to the drug trafficking industry. "Insofar as we can work together and confront this scourge together, we are going to be much more effective,” said Santos.

Calderon sounded similar notes: “Colombia and Mexico are more united than ever in the fight against transnational organized crime and are also ready to collaborate with third countries in the region to combat this scourge, particularly with our brother nations in Central America.”

But while nothing from this specific meeting seems likely to radically alter the way Colombia and Mexico attack the drug trade, the fact of the talks and their optimistic tenor does continue a pattern of collaboration. Meanwhile, media accounts suggest that cooperation between Mexican and Colombian security forces has been on the rise in recent months.

As the Washington Post reported in January, some 7,000 Mexican police officers, detectives, and prosecutors have received training in Colombia in recent years. A March report from the Los Angeles Times detailed Colombia’s role as a growing military training hub for various Latin American forces, with Mexico sending helicopter pilots through a 32-week course at a price tag of $75,000 a head.

Working with Colombia offers two main benefits: first, as a result of decades of fighting against leftist insurgents and drug syndicates even more aggressive than those in Mexico today, the Colombians have a great deal of relevant experience for nations presently witnessing a surge in organized crime.

And second, because the Colombians have worked so closely with the U.S., training in Colombia offers the chance to benefit from American know-how without the political complications of greater U.S. involvement in Mexican affairs.

But the collaboration between Mexico and Colombia is not just a matter of convenience and ideological similarities: it is a direct result of the dynamics of a cocaine trade in which the Colombian gangs are the foremost producers and the Mexican counterparts serve as gatekeepers to the U.S., the biggest market. In other words, both sides are vital and complementary players.

Colombian operators have long been a fixture in Mexico. In the days when Colombian groups controlled the drug trade, their representatives would handle drug shipments all the way north to Mexico and the U.S. In one more recent incident, Ever Villafañe, who had escaped from prison in his native Colombia in 2001 and was one of the Beltran Levya’s chief links to the South American country, was arrested in Mexico in 2008.

However, with the decline of Colombia's cartels and the rise of more decentralized, fractured networks at the helm of the drug trade, it has become increasingly common for Mexican operatives to appear in Colombia. The Sinaloa Cartel has increased its links to South American production, and reports of the group operating in Colombia and neighboring countries have grown. As InSight Crime reported in March, Colombian authorities accused three Sinaloa lieutenants of operating from within national territory, as well as accusing the group of working with the FARC to smuggle coltan.