Next, the narcocorridos will sing about the pilotless planes above the heads of their patrons.

It used to be that the Department of Homeland Security flew drones over the U.S.-Mexican border to keep watch for illegal immigrants. That proliferation of military technology to a civilian mission isn’t without its share of malfunctions: not only did the communications systems occasionally fritz out, but on at least one occasion, a small drone — the property of the Mexican government — crashed into an El Paso backyard. But now the drones are taking on a new mission: hunting drug gangs in Mexico.

According to a previously undisclosed agreement between President Obama and his Mexican counterpart, Felipe Calderon, the Pentagon is authorized to fly unmanned surveillance flights over Mexico, a big expansion of U.S.-Mexico information sharing on counternarcotics. One of drones used for the mission is the Air Force’s Global Hawk, reports the New York Times, soaring at up to 60,000 feet with a multitude of sensors. (Calm down, it’s unarmed.)

It’s not known how many flights the Global Hawk has made above Mexico. But the Times reports that the drones helped catch the killers of Jaime Zapata, one of two special agents of the U.S. Immigration and Customs Enforcement service shot and killed on the road between Mexico City and Monterrey.

The drone flights are part of an expansion of U.S.-Mexican anti-drug cooperation that’s risen to match the furious violence brought by the drug cartels. (Violence, the Mexican government is quick to point out, that relies on trafficked American guns.) In the heart of Mexico City, at 265 Paseo de la Reforma, an office building is stacked with U.S. intelligence, law enforcement and military officials from the FBI, the CIA, the NSA and many other agencies.

According to the Times, a second “fusion center” to merge U.S. and Mexican intel will soon open. It’s not clear if that center, the previous one, or a different facility receives data swooped up by the Global Hawks. Nor is it clear what role if any the Mexican government plays in directing the drone flights. An anonymous U.S. official quoted by the Times’ Ginger Thompson and Mark Mazzetti merely assures, “counternarcotics activities [are] conducted at the request and direction of the Mexican government.”

Still, welcome to yet another civilian mission for the drones. A much smaller unmanned spy vehicle, colloquially known as the Flying Beer Keg, is now in the hands of Miami-Dade police (who, it should be noted, also hunt for drugs, if Rick Ross is to be believed.) And while the Department of Homeland Security isn’t so enthusiastic about using drones for bomb detection inside the U.S., the Federal Aviation Administration is slowly warming to the idea of remotely piloted planes inside U.S. airspace. There are also Global Hawks flying in support of Japan’s earthquake and tsunami relief efforts.

No wonder Defense Secretary Robert Gates told the Air Force that the era of the drone will outlast the Iraq and Afghanistan wars. Terrorists and insurgents have already had to make adjustments to the drones hunting them overhead. Now it’s the cartel’s turn.

Photo: U.S. Air Force