Why does afghanistan get the blame for 911 when 15/19 of the alleged hijackers were saudis?

I think the headquarters must have been in Afghanistan. If you remember, it wasnt the COUNTRY that got the blame at all, it was al quaida. Also, we rely so much on saudi oil that there was no way the admisistration was about to go attack the saudi's lol. If they took away our oil we'd be screwed. Its a crappy situation but they have to "ignore" the fact that they were saudis as long as we need that oil from what i've been told.