But senior agency officials, still persuaded, as they had told President George W. Bush and his staff, that he was an important Qaeda leader, insisted that he must know more.“You get a ton of information, but headquarters says, ‘There must be more,’ ” recalled one intelligence officer who was involved in the case. As described in the footnote to the memo, the use of repeated waterboarding against Abu Zubaydah was ordered “at the direction of C.I.A. headquarters,” and officials were dispatched from headquarters “to watch the last waterboard session.”