There were others who helped keep the secrets of the base. The United Nations Assistance Mission in Afghanistan, or UNAMA, which was responsible for monitoring human rights abuses, was informed that Naseer's death in Gardez probably involved "torture and other cruel and inhuman treatment" by Special Forces troops. But U.N. officials acknowledge they did not report it to American authorities for at least 13 months, and U.S. officials say it was never reported at all.

The provincial governor helped conceal the mistreatment by arranging for the late-night removal of Naseer's body from the military base. He also ordered the abrupt transfer of the other detainees from the base to the custody of the local police chief after they had been held many days beyond what military procedures allowed.

Though U.S. commanders in Afghanistan said they did not know about the death, word spread throughout Paktia province, according to Gen. Hajji Abdul Sattar, the Paktia attorney general for intelligence. He said no one spoke out or complained, however, because "people were scared that … the same thing would happen to them."

The Army's Criminal Investigation Command has been examining both deaths and apparent cover-ups for two years, since learning about them from The Times and the Crimes of War Project, a Washington-based nonprofit educational organization, which first confirmed Naseer's death.

ODA 2021's missions and tactics became markedly more aggressive after Waller took charge of the Special Forces detachment in February 2003, a month before the questionable deaths in Wazi and Gardez. He recently had been reassigned from another Special Forces unit, where some of his men complained that his gung-ho leadership style put them at unnecessary risk.

Waller was characterized by several 20th Group officials as deeply affected by the Sept. 11 attacks and having come to Afghanistan "spoiling for a fight."

In Gardez, he was able to set his sights squarely on Pacha Khan, the warlord who had been destabilizing the countryside for months.

Pacha Khan's men were suspected of extorting illegal payments from truckers on the road from Gardez to Khowst, supporting anti-government forces, and staging an ambush that wounded the ODA's battalion chief during a Thanksgiving trip to Gardez.

But at the Pentagon and State Department, Pacha Khan was regarded as a political figure and thus a problem for the new Afghan government, not the U.S. military. The Special Forces team chafed at the political constraints on its freedom to go after him.

Local U.N. officials said they were struck by how deeply personal the conflict between the team and the warlord had become. One of the officials, who spoke on condition of anonymity, recalled that one Green Beret likened the team's rivalry with Pacha Khan to a blood feud.

Another U.N. official said the same American soldier had told him that "he was so frustrated with [Pacha Khan] that he was going to kill him."

Tea at Sato Kandaw

Unmanned Predator aircraft patrolled the skies over Paktia province, their cameras trained on the 17 checkpoints along the mountain road linking Khowst and Gardez. What they recorded convinced U.S. intelligence officials that trucks hauling firewood and produce were again being stopped and forced to pay bribes.

At the most infamous checkpoint, atop Sato Kandaw Pass, drivers typically had to pay $10 or $15, according to a March 2, 2003, Army intelligence report. The money was being split between Pacha Khan and a former Taliban official, Jalaludin Haqqani, the report said.

Situated on a bend overlooking a sparsely vegetated valley, the Sato Kandaw checkpoint consisted of living quarters and a small mosque used as an armory. The post was controlled by a former Pacha Khan lieutenant named Ahmad Naseer, better known as Commander Parre. He had recently defected to the Afghan government in exchange for $3,000 and a truck provided by the CIA. He said he saw the future of the country with the Americans, not with Pacha Khan.

Despite the change in management, reports of shakedowns persisted, along with complaints that female travelers were being harassed and that a young boy was being held as a sex slave.

Sato Kandaw was enough of a concern that Raz Mohammed Dalili, then the governor of Paktia, took the unusual step of asking American troops to remove the checkpoint. Dalili, in an interview, said he had made his request to a Special Forces soldier named Mike.

There was no ODA 2021 member named Mike at the time, military documents show. However, Sgt. 1st Class Michael E. MacMillan, an intelligence analyst and member of the regular Army's 7th Special Forces Group at Ft. Bragg, N.C., was then working with the Gardez unit.

Described in correspondence from Waller as the team's "intelligence agent," MacMillan was assigned to conduct interrogations and collect information for combat operations, including one at Sato Kandaw, according to several people familiar with the team. MacMillan, contacted at his home in North Carolina, declined to be interviewed for this report and shut his door.

Parre and his men had their guards down when the ODA (for Operational Detachment Alpha) arrived at Sato Kandaw on the chilly morning of March 5. He said that they shook hands and that the soldier he knew as Mike asked to talk over green tea.