Yeah, because re-aligning bases that were aimed at Cold War threats makes no sense whatsoever.
I will not further this BRAC argument, because I don't think it holds much weight (i.e. squorch is correct here). Far more detrimental was the cannibalization of the Intel agencies and their budgets/ assets that occurred during Clinton's watch.
In defense of the intel agencies, it was incredibly difficult for these agencies to prevent this or any particular attack with a high level of trade craft (like 9/11). That is why a fundamental shift from a "law enforcement" strategy to a "war on terrorism" strategy (however inappropriately named since terrorism is merely a tactic) had to occur.
The bottom line is that Clinton had many chances to get bin Laden, who had attacked the US several times (our ships, embassies, and home soil). Clinton's chances to get UBL in Sudan and Afghan were better than anything Bush had once he came into office, especially after the start of OEF--because SUPRISE was lost. Getting bin Laden before 9/11 was much easier than getting him after.
But, Clinton governed by opinion polls. This caused him to be very popular, but also led him to neglect issues most Americans were not concerned with. By no means is Clinton "responsible" for 9/11, but he was in the best position to prevent it, and it was his responsibility to do so.