What conclusion should be drawn from the Fort Hood shooting?

Posted Nov. 09, 2009, at 1:40 p.m.

Nidal Hasan, according to police, shot and killed 13 of his fellow soliders. The Army major was a psychiatrist, a Muslim of Palestinian descent and an apparent opponent of the wars in Iraq and Afghanistan. What do you make of this tragedy? Is this evidence of a global struggle against radical Islam? Evidence of the toll the wars are taking on our troops? Or was this the act of a mentally unstable man? Should the Army have provided more screening to learn whether people like Maj. Hasan are having trouble coping?