"...[John Muhammad] Williams’s unit was sent to Operation Desert Storm to clear mines and bulldoze holes in enemy lines. A few nights before the invasion of Iraq, Sergeant Berentson awoke in the early hours to find his tent, with 16 sleeping men inside, on fire. Someone had tossed in a thermite grenade. Berentson, who was fed up with Williams’s insubordination, immediately suspected Williams and told the Army’s Criminal Investigative Division. Berentson says he last saw Williams being led away in handcuffs. Williams’s military records make no mention of the incident; indeed, they suggest Williams had a distinguished gulf-war stint. But...