It isn't a question now of whether or not the warnings were specific. They never are.
It's a question of whether or not 9/11 should have been anticipated, given the warnings. And whether plans should have been in place to deal with such a scenario.
It's been common knowledge since 1993 that Islamic terrorists associated with Osama Bin Laden have wanted to hijack planes and fly them into buildings.
Had there been such plans, there might have been enough time to deal with the hijacking as it was occuring. At very least, the second the FAA became aware that 4 planes in US airspace had been hijacked simultaneously, fighter aircraft should have been scrambled.
And in 1998, Time Magazine narrowed the targets to DC and New York. How much more information did this administration think was necessary before it acted?