WASHINGTON - The National Security Agency first began to conduct warrantless eavesdropping on telephone calls and e-mail messages between the United States and Afghanistan months before President Bush officially authorized a broader version of the agency's special domestic collection program, according to current and former government officials.
The security agency surveillance of telecommunications between the United States and Afghanistan began in the immediate aftermath of the Sept. 11, 2001, attacks on New York and Washington, the officials said.
The agency operation included eavesdropping on communications between Americans and other individuals in the United States and people in Afghanistan without the court-approved search warrants that are normally required for such domestic intelligence activities.
On Saturday, President Bush confirmed the existence of the security agency's domestic intelligence collection program and defended it, saying it had been instrumental in disrupting terrorist cells in America.
After the Sept. 11 attacks, the Bush administration and senior American intelligence officials quickly decided that existing laws and regulations restricting the government's ability to monitor American communications were too rigid to permit quick and flexible access to international calls and e-mail traffic involving terrorism suspects. Bush administration officials also believed that the intelligence community, including the Central Intelligence Agency and the N.S.A., had been too risk-averse before the attacks and had missed opportunities to prevent them.
In the days after the attacks, the C.I.A. determined that Al Qaeda, which had found a haven in Afghanistan, was responsible. Congress quickly passed a resolution authorizing the president to conduct a war on terrorism, and the security agency was secretly ordered to begin conducting comprehensive coverage of all communications into and out of Afghanistan, including those to and from the United States, current and former officials said.
It could not be learned whether Mr. Bush issued a formal written order authorizing the early surveillance of communications between the United States and Afghanistan that was later superseded by the broader order. A White House spokeswoman, Maria Tamburri, declined to comment Saturday on the Afghanistan monitoring, saying she could not go beyond Mr. Bush's speech.
Current and former American intelligence and law enforcement officials who discussed the matter were granted anonymity because the intelligence-gathering program is highly classified. Some had direct knowledge of the program.
The disclosure of the security agency's warrantless eavesdropping on calls between the United States and Afghanistan sheds light on the origins of the agency's larger surveillance activities, which officials say have included monitoring the communications of as many as 500 Americans and other people inside the United States without search warrants at any one time. Several current and former officials have said that they believe the security agency operation began virtually on the fly in the days after the Sept. 11 attacks.
The early, narrow focus on communications in and out of Afghanistan reflected the ad hoc nature of the government's initial approach to counterterrorism policies in the days after Sept. 11 attacks.
But after the United States-led invasion of Afghanistan succeeded in overthrowing the Taliban government in late 2001, Al Qaeda lost its sanctuary, and Osama bin Laden and other Qaeda leaders scattered to Pakistan, Iran and other countries. As counterterrorism operations grew, the Bush administration wanted the security agency secretly to expand its surveillance as well. By 2002, Mr. Bush gave the agency broader surveillance authority.
In the early years of the operation, there were few, if any, controls placed on the activity by anyone outside the security agency, officials say. It was not until 2004, when several officials raised concerns about its legality, that the Justice Department conducted its first audit of the operation. Security agency officials had been given the power to select the people they would single out for eavesdropping inside the United States without getting approval for each case from the White House or the Justice Department, the officials said.
While the monitoring program was conducted without court-approved warrants, senior Bush administration officials said the far-reaching decision to move ahead with the program was justified by the pressing need to identify whether any remaining ''sleeper cells'' were still operating within the United States after the Sept. 11 attacks and whether they were planning ''follow-on attacks.''
Mr. Bush, in his speech on Saturday, cited the disruptions of "terrorist cells" since Sept. 11 in New York, Oregon, Virginia, California, Texas and Ohio as evidence of a very real threat. And he pointed to overseas communications by two of the Sept. 11 hijackers who were living in the San Diego area as evidence that the security agency needed the power and flexibility to track international communications.
The two men "communicated to other members of Al Qaeda who were overseas," Mr. Bush said. "But we didn't know they were here, until it was too late.''
In his speech, Mr. Bush pointed to the layers of oversight and review that are built into the secret spying program to ensure that it is ''consistent with the letter and intent of the authorization.''