“Al-Qaeda’s masterstroke in assassinating [Northern Alliance leader] Ahmad Shah Massoud [on September 9, 2001] just two days before the September 11 operation certainly was a calculated maneuver to curry favor with [the leader of the Taliban, Mullah Mohammad] Omar. Massoud’s death removed the last major impediment to Omar’s total control of Afghanistan, which, in turn, would further Taliban claims for formal international recognition. …That assassination helped mask what appears to have been Osama’s calculated failure to inform his host of Al-Qaeda’s plans for striking New York and Washington, which soon unseated Omar and deprived Osama of his Afghan sanctuary.”
– Jonathan Randal, Osama, Pages 240-241