They singled out high-ranking militants that led the group of fighters that attacked the team of United States soldiers, including Green Berets, and their Nigerien counterparts. But the officials at the meeting also identified roughly 20 low-level fighters, according to the documents that outline the discussion. The Pentagon has said that the American team involved in the ambush killed 20 to 25 militants.
At the meeting, the officials also discussed methods to help track the militants who participated in and helped orchestrate the ambush — an endeavor that could take years. The American military and national intelligence agencies are still searching for the militants responsible for the Sept. 11, 2012, strike on diplomatic compounds in Benghazi, Libya, that killed four Americans, including Ambassador J. Christopher Stevens.
French and Nigerien security officials say ISIS in the Greater Sahara has 40 to 60 core members. It is often joined by sympathetic villagers, and it has temporary alliances with other local groups — two avenues of support that can be mobilized quickly.
The branch and its leader, Adnan Abu Walid al-Sahraoui, sought the recognition of the Islamic State in 2015 after breaking from Al-Mourabitoun, a Qaeda splinter group, according to a statement released by the State Department.
“This ambush made us really realize the threats out there are more organized than we thought,” Col. Maj. Moussa Salaou Barmou, the head of the Nigerien Special Forces, said in an interview last month, noting that the militants have also threatened village elders if they cooperate with the authorities. “Villages and hide-outs are only one or two hours apart, and the terrorists can react very fast.”
Mr. Cheffou has been connected to the kidnapping of an American aid worker, Jeffery Woodke, in Niger. In October, American intelligence agencies tracked his location to the Niger-Mali border by a ping from his cellphone. Mr. Cheffou was gone by the time the Special Forces team arrived at his camp, but hours later he was coordinating the fated ambush, according to the documents.