By many assessments, including his own, the lawyer, Navy Lt. Alaric Piette, is completely unqualified to represent Abd al-Rahim al-Nashiri, a Saudi man accused of orchestrating the bombing of the American destroyer Cole in 2000. Though he was trained to hunt down the most dangerous terrorists in the world, nothing prepared him to defend someone accused of carrying out terrorist acts.

“On another day, I could have easily taken my client out. I know it seems like a contradiction,” Lieutenant Piette said as he stood in the tropical glare outside the dust-colored court building here, which is ringed by razor wire and sniper netting. “But in a lot of ways being a SEAL and being a defense attorney — you’re doing the same thing. You’re defending the Constitution.”