In the deadliest assault on a military base in the U.S. in history, Major Nidal Malik Hasan rampaged through Fort Hood in Texas on Nov. 5, killing 13 people including 12 troops and wounding more than 30. An Army psychiatrist charged with caring for soldiers scarred by a war he was scared to join, Hasan was cast by some as a shattered loner driven to madness by the prospect of fighting against fellow Muslims in Afghanistan. Others feared that he was a harbinger of the future of terrorism: single-person cells activated by little else than virtual adherence to an extremist creed headquartered in a cave. But as critics noted, before Hasan snapped, he hoisted a series of warning signs, including a PowerPoint deck castigating U.S. foreign policy, Internet posts glorifying suicide bombers and e-mail exchanges with a radical Yemeni cleric. Critics have suggested that Army officials failed to respond to the barrage of red flags because they feared accusations of racial profiling.