Last week the Associated Press reported the discovery of a mass grave in Putumayo containing the mutilated bodies of 105 people believed to have been murdered by right wing paramilitaries from 1999 - 2001.  The killings took place while Gen. Mario Montoya, now commander of Colombia's armed forces, was leading a massive offensive in the department. Throughout that offensive, the U.S. continued providing weapons, intelligence, training and equipment to the counternarcotics battalions of Montoya's Joint Task Force South despite the fact that the State Department knew those battalions were working closely with Montoya's 24th Brigade -- a unit linked to the paramilitaries responsible for that mass grave.  Anne Patterson, who now oversees most U.S. operations in Colombia as Assistant Secretary of State for International Narcotics and Law Enforcement, served as U.S. Ambassador to Colombia at the time and had been warned of the close collaboration between the paramilitaries and Montoya's troops.  The discovery of the mass grave raises serious questions about Patterson's commitment to breaking the ties between the Colombian military and the paramilitary groups that are responsible for not only the country's worst attrocities but also the production and export of most of the cocaine that reaches the U.S.