Washington

IN March 2002, John M. Poindexter, a former national security adviser to President Ronald Reagan, sat down with Gen. Michael V. Hayden, the director of the National Security Agency. Mr. Poindexter sketched out a new Pentagon program called Total Information Awareness, that proposed to scan the world’s electronic information — including phone calls, e-mails and financial and travel records — looking for transactions associated with terrorist plots. The N.S.A., the government’s chief eavesdropper, routinely collected and analyzed such signals, so Mr. Poindexter thought the agency was an obvious place to test his ideas.

He never had much of a chance. When T.I.A.’s existence became public, it was denounced as the height of post-9/11 excess and ridiculed for its creepy name. Mr. Poindexter’s notorious role in the Iran-contra affair became a central focus of the debate. He resigned from government, and T.I.A. was dismantled in 2003.

But what Mr. Poindexter didn’t know was that the N.S.A. was already pursuing its own version of the program, and on a scale that he had only imagined. A decade later, the legacy of T.I.A. is quietly thriving at the N.S.A. It is more pervasive than most people think, and it operates with little accountability or restraint.

The foundations of this surveillance apparatus were laid soon after 9/11, when President George W. Bush authorized the N.S.A. to monitor the communications records of Americans who analysts suspected had a “nexus to terrorism.” Acting on dubious legal authority, and without warrants, the N.S.A. began intercepting huge amounts of information.