The OP is completely off base on why Massoud was taken out.

It was prep for 9/11 to be sure. But it was a move by al Qaeda/Taliban to weaken the opposition in Afghanistan. They did not want Massoud as a US ally against the Taliban. They knew the US would get involved militarily after the attacks. Al Qaeda has stated their goal is to involve the US in conflicts across the globe to drain our treasury and weaken us.

Massoud would have been a powerful US ally and would have led to unifying Afghanistan. The Taliban and al Qaeda used the blueprint we gave them in the 1980s to bog down the Soviet forces in an unwinnable conflict against us.