Campaign To Justify Spying Intensifies

Although the two speeches provided some new information about the NSA program, many crucial details remain unclear. Hayden, for example, did not describe whether the program consisted of listening to conversations or getting phone numbers and callers' names or both. He also did not describe what happens to the information once it is collected by the NSA.

In addition, Bush and Hayden provided varying and sometimes contradictory descriptions of who has been targeted by the NSA spying. Bush said the program involved a "known al Qaeda suspect, making a phone call into the United States." Hayden said one of the ends of an international call must be overseas but did not indicate that the suspected al Qaeda link must be foreign.

At various points in his remarks, Hayden said the program targeted communications "that we have reason to believe are al Qaeda communications," that involve "someone we believe is associated with al Qaeda" or that "we have a reasonable basis to believe involve al Qaeda or one of its affiliates."

Hayden said he could not provide more details about how the program works because it would give ammunition to terrorist enemies.

Hayden echoed a claim earlier this month by Vice President Cheney that, if the NSA program had been in place prior to the Sept. 11, 2001, attacks, "it is my professional judgment that we would have detected some of the 9/11 al Qaeda operatives in the United States."

Like Cheney, however, Hayden did not mention that the NSA, CIA and FBI had significant information about two of the leading hijackers as early as January 2000 but failed to keep track of them or capitalize on the information, according to the Sept. 11 commission and others. He also did not mention NSA intercepts warning of the attacks the day before, but not translated until Sept. 12, 2001.

In addition to the NSA eavesdropping ordered by Bush, the former NSA director discussed his own initiative after the Sept. 11 attacks to sharpen and increase the focus of foreign collection on potential terrorists and to provide more information to the FBI. "We turned on the spigot of NSA reporting to the FBI in, frankly, an unprecedented way," he said.

He said the warrantless domestic eavesdropping program allowed the NSA to act more rapidly and with less information than possible under FISA. That law requires convincing a special court that investigators have probable cause to believe a subject may be linked to a foreign power or terrorist group. And although the law allows emergency surveillance or searches for 72 hours, Hayden suggested that still would require too much evidence to proceed in many cases.

Staff writer Peter Baker and researcher Julie Tate contributed to this report.