Was the failure to capture Osama bin Laden at Tora Bora just "an unfortunate footnote to an otherwise upbeat story"? No, argues the New Republic's Peter Bergen in what he calls "the definitive account" of the al Qaeda leader's escape: It was "one of the greatest military blunders in recent U.S. history." Constructing his history from the accounts of CIA and military operatives as well as al Qaeda members present with bin Laden in 2001, Bergen casts the U.S. forces' inability to catch or kill the terrorist as the result of an overextended military and an overly cautious strategy that put much of the fighting in the hands not of U.S. troops but of Afghan proxies. "When [the Bush administration] had an opportunity... to decapitate [al Qaeda]," says John Kerry, "they never showed up."