The Bush administration made a fateful choice to pursue 9/11 as an act of war, rather than as a crime. The 20 years since have been a direct consequence of this action.
Had the United States pursued bin Laden as a criminal, the Taliban would have given him up to the Hague. There would have been a trial. The United States would have been the sympathetic victim. Of course, in The People vs. Osama bin Laden, the defense would have brought to light bin Laden's work for the CIA with the mujahedin, his inroads with the Saudi royal family and the general skullduggery of American foreign policy.
A Gore administration would have happily sacrificed the CIA's South Asia program on the altar of geopolitics. There would have been a reckoning, there would have been outrage on the right, but the world would have ended up a closer, more tight-knit place. The consequences of empire would have been held up for all to see and the price of hegemony discussed ad nauseum by all sides.
But Bush's dad was the head of the CIA, Cheney and Rumsfeld were black bag scumbags going way back, and tying a Reichstag fire to the Project for a New American Century was an opportunity the neocons couldn't miss.
Results were predictable. Those of us with any insight into foreign policy saw this coming a mile away; I personally didn't think we'd be in Afghanistan for 20 years but 5-10 was inevitable.
Nobody went to war over Ramzi Yousef.