Philip Caputo - in this December's The Atlantic
In the almost three years since President Felipe Calderón launched a war on drug cartels, border towns in Mexico have turned into halls of mirrors where no one knows who is on which side or what chance remark could get you murdered. Some 14,000 people have been killed in that time—the worst carnage since the Mexican Revolution—and part of the country is effectively under martial law. Is this evidence of a creeping coup by the military? A war between drug cartels? Between the president and his opposition? Or just collateral damage from the (U.S.-supported) war on drugs? Nobody knows: Mexico is where facts, like people, simply disappear. The stakes for the U.S. are high, especially as the prospect of a failed state on our southern border begins to seem all too real...(snipped)...concluded in a recent report that 17 of Mexico’s 31 states have become virtual narco-republics, where organized crime has infiltrated government, the courts, and the police so extensively that there is almost no way they can be cleaned up. The drug gangs have acquired a “military capacity” that enables them to confront the army on an almost equal footing.

Ref: http://www.theatlantic.com/doc/200912/mexico-drugs?pid=ynews

With Mexico threatening to become a failed state, what are the consequences for the US, and how should/can the US cope with this threat?