On Sunday, CIA director Michael Hayden warned on Meet the Press that a reconstituting al Qaeda was preparing operatives in Afghanistan who would draw no attention while passing through U.S. airport checkpoints.

Exactly how vulnerable are we right now to a significant terrorist attack? No one can answer that question with any certainty. What we can say with assurance is that even as George W. Bush has overseen the single most far-reaching reorganization of the U.S. intelligence community (IC) since the CIA was created in 1947, his single greatest failure as a president might well be that American intelligence remains mired in bureaucratic mediocrity.

That bureaucratic mediocrity has already exacted a high price. A major installment came due when the CIA and FBI missed the Sept. 11 plot. A second came a year later with the CIA’s “slam-dunk” assessment that Saddam Hussein was acquiring weapons of mass destruction. In 2004, Congress radically reshuffled U.S. intelligence, creating a new intelligence “czar” — the Director of National Intelligence (DNI) — whose office, the ODNI, would assume many of the coordinating functions that had formerly been in the hands of the CIA.

This shift was intensely controversial. One of the most frequent criticisms was that grafting a new bureaucracy on top of an already dysfunctional system would only compound existing problems. Four years later, how is the ODNI faring?

I offer a partial answer to that question in The Real Bush Intelligence Failure in today’s Wall Street Journal.