At the end of last year, with the appearance of James Risen's State of War: The Secret History of the CIA and the Bush Administration (Free Press), it was revealed that after 9/11 President George W. Bush authorized the National Security Agency—the low-profile but huge intelligence outfit based in Maryland at Fort George C. Meade that monitors electronic communications—to eavesdrop on communications between individuals outside the United States and citizens inside the country. Previously such wiretapping could be done only with the authorization of a special court established by a 1978 law, the Foreign Intelligence Surveillance Act (FISA).

The Bush White House has argued that the wiretapping was justified by circumstances and was both legal—under the congressional resolution that authorized military action against Iraq—and constitutional, as part of the inherent powers of the president as commander in chief [see photo, "In Defense"]. Critics argue that the wiretapping was unequivocally contrary to the 1978 law, as well as unconstitutional. In an open letter to Congress, 14 constitutional scholars said that "it is always open to the president...to seek to change the law," but that "the president cannot simply violate criminal laws behind closed doors because he deems them obsolete or impracticable."

Journalist James Bamford [photo] is the author of two books about the ultrasecretive NSA, The Puzzle Palace (Houghton-Mifflin, 1982), and Body of Secrets (Doubleday, 2001). His A Pretext for War (Doubleday), about the decision to invade Iraq, was published in 2004. For the record: he is party, with four other people, in a lawsuit brought against the Bush administration by the American Civil Liberties Union (ACLU), in New York. The suit seeks to halt the NSA's warrantless domestic eavesdropping and to determine whether the electronic communications of parties to the suit have been monitored.

Were you surprised by the disclosure that President Bush had in effect authorized wiretapping of people in the United States without court warrant?

Yes, because for 30 years the NSA had managed to go about its eavesdropping obeying the laws.

Had your NSA sources told you that after 9/11 they were staying well within the limits of the 1978 law?

I interviewed the director of the NSA a number of times, and I've talked to a lot of people there, and none of them indicated that they were unhappy with FISA or going around it.

So, did you feel betrayed?

I don't know if "betrayed" is the right word. I felt concerned, because I had spent a lot of time defending the NSA in front of the European Parliament [in Strasbourg, France] and other places where I felt that the agency was being accused wrongly. I felt a sense of disillusionment, I guess.

What do you think prompted the president to authorize warrantless surveillance of U.S. citizens living in the United States?

After 9/11, there were a number of meetings within the intelligence community. I think that the NSA came up with the idea that the one area where they're not able to tap into very efficiently is the American citizenry, because they have to go through the FISA court. That means every time the agency wants to eavesdrop on somebody, they have to show probable cause that the individual is somehow connected to terrorism. Apparently the NSA suggested dropping that standard and instead using a much lower standard, called "reasonable belief."