What if Bush and the USA had assumed the moral high ground?
OK, Bush could not (not would not) have understood that as a choice, as I feel his identification with the US and its gungho reactions to foreign affairs made him feel his (and the USA's) manhood was threatened if they didn't respond with guns blazing. Really, he lacked the intellectual aptitude to do anything other than he did. He knew little to nothing of the Middle East and the problems and tensions there and picked the most vulnerable Middle-Eastern target (isolated/friendless).
But say if the USA had forgiven, isolated the culprits and their mentality, gone after those clearly involved and dealt with them appropriately, but otherwise acted with moral certainty and absolved a culture and people from responsibility. At that stage, the USA could not perhaps have done that but strong and credible leadership might have made the difference, and consequently saved at least a million lives.