Attorney General Eric Holder was just months into the job when he announced plans to prosecute the accused mastermind of the Sept. 11 attacks and other alleged co-conspirators in a New York courtroom, rather than through the Guantánamo Bay military commission process. It was an audacious idea, but immediately beset by political opposition and public safety concerns. The Obama administration’s eventual decision to walk away from the proposal was a stinging defeat for Holder and a reminder of the complexities of the legal fight against terrorism. […] … (U)nder his watch, the department authorized targeted drone strikes against Americans abroad,...