When confronted with such questions as why it took the U.S. a full decade to kill Osama bin Laden, there’s a tendency to engage in Monday morning quarterbacking: evaluating past decisions in light of information we have now, and assuming alternative courses of action would have been superior only because they are different.
In the case of the search for Bin Laden, there are a couple of clear errors, and a lot that even now we don’t know.
One clear mistake is the failure to dedicate additional troops to an operation in the Tora Bora mountains in December 2001. As the terrorism analyst Peter Bergen wrote in "The Longest War, Tora Bora represented “the last, best chance to capture bin Laden” — until now.
A second error was the eagerness with which the U.S. went to war in Iraq thereafter, causing the diversion of resources from Afghanistan/Pakistan. The Iraq war, as Vice President Dick Cheney said, was driven in part by our thinking that “we need to battle them (the terrorists) overseas so we don’t have to battle them here at home.” Criticizing this paradigm is not just Monday morning quarterbacking.