I'm not sure who "they" are or what "decision" you refer to, but this is yesterday's New York Times description of life in Kabul, the most likely target of U.S. retalliation:


". . . roaming clusters of widows beg in the streets, their palms seemingly frozen in a supplicant pose. Withered men pull overloaded carts, their labor less costly than the price of a donkey. Children play in vast ruins, their limbs sometimes wrenched away by remnant land mines. The national life expectancy, according to the central statistics office, has fallen to 42 for males and 40 for females. The prolonged drought has sent nearly a million Afghans — about 5 percent of the population — on a desperate flight from hunger. Some have gone to other Afghan cities, others across the border. More than one million are ‘at risk of starvation,' according to the United Nations."


From "Taliban Plead for Mercy to the Miserable in a Land of Nothing"


Just what decision did these people make that warrants their incineration?

What greater ability to determine the course of events distinguishes them from the victims of the airliner bombings?

What would distinguish the bombers?