The suspect Khalid al - Awlaki was killed in a 2011 drone strike . The U.S. said he was top operative for al Qaeda in Yemen . The document said the government had no feasible way to arrest al-Awlaki and concluded the authorization of military force against al Qaeda applied to him as it would a non citizen . Government sought to keep memo secret , saying release could harm national security . Memo said that force authorization against al Qaeda in general belonged to al - Awlaki .
The suspect Khalid al - Awlaki was killed in a 2011 drone strike . The U.S. said he was top operative for al Qaeda in Yemen . Government sought to keep memo secret , saying release could harm national security . Memo said that force authorization against al Qaeda in general belonged to al - Awlaki .