I think the failure to catch and kill OBL in the immediate wake of the invasion of Afghanistan was a major strategic failure. It revitalized jihadism when its main representative evaded capture to taunt us again and again. It showed potential jihadis that even when fully roused from its slumber, the U.S. was not invincible.

A combination of other factors has sustained jihadism. OBL has become a cultural marker now, an Islamist Che Guevara. Killing or capturing him now would still be a major tactical victory, but it would not be the potential deathblow to Islamism that it would have been back in 2001.