[nebula8804]

It was a catastrophic failure in terms of money spent, lives lost and enduring repetitional damage on the US that continues to this day. Vietnam was a harbinger of this but Afghanistan/Iraq cemented the notion that if you operate on long term timescales you can beat the US.

UBL may not have achieved his primary goal but he got many concessions: Americans lost many freedoms, trust in government is significantly lower compared to pre 9/11 and given what happened on Jan 6 and everything that led up to it, we may look back at 9/11 as the point which set the stage for the eventual breakup of the union.