Terrorist Surveillance Program Designed to Detect, Prevent Attacks

"This is focused on al Qaeda," said Air Force Gen. Michael V. Hayden, principal deputy director of national intelligence and former director of the National Security Agency, during a "Fox News Sunday" interview. "The only justification we have to undertake this program is to detect and prevent attacks against the United States."

Through the president's authorization of the program, the NSA can monitor incoming and outgoing international phone calls when there is reasonable belief that either caller has an al Qaeda connection. Opponents have argued that the Foreign Intelligence Surveillance Act allows for the same thing when probable cause exists.

But FISA requires paperwork between the NSA and the attorney general, thereby slowing the process considerably, Hayden said. He pointed out that the attorney general has said the FISA process does not allow for the speed and agility to do what the surveillance program is designed to do.

"Speed is very important," Hayden said. "This (gives us agility to get up on communications, in many cases in a matter of hours rather than days, weeks or even months. That's what the key to this program is, again -- detect and prevent."

The legal aspects of the program are being debated, though, he acknowledged. Some would like to see it authorized with more legislation, but that could negate the program's usefulness, Hayden said on the ABC program "This Week."

"Whatever it is we do in the future has to be done in a way that doesn't reveal our tactics, techniques and procedures to the enemy," he told host George Stephanopoulos, explaining that further legislation of the program may do just that.

For those who are wary about calling overseas for fear of being monitored, Hayden said, that's not likely to happen. The NSA isn't monitoring all communications and sifting through them, he said. Al Qaeda is the program's focus.

"We really don't have the time or the resources - linguists - to linger to, go after (communications) that aren't going to protect the homeland," he said. "If you're not relevant, if the intercept isn't relevant ... we don't need it. We go on to those things that actually help us accomplish the mission."

And whether or not conversations conducted inside the United States would be helpful to conducting that mission, they're off limits, he said.

"Even after the president's authorization, if Osama bin Laden ... crossed the bridge (and) ... he's in Niagara Falls, N.Y., and he calls Pittsburgh, I still can't cover him," Hayden said.

The general said the intelligence community not only is monitoring possible al Qaeda communications to and from the United States, but also is studying the tapes the group has recently released. Hayden said there's the sense the group may be releasing the tapes as a "proof of life."

"The al Qaeda leadership may be on their back foot and the rest of the organization may see that," he said. "These tapes may be an attempt on their part to kind of reestablish authenticity with their followers."

On "Fox News Sunday," host Chris Wallace turned the topic to Iran and the International Atomic Energy Agency's reporting of the country to the United Nations Security Council.

Hayden said the overall estimate of the intelligence community is that Iran is very determined to acquire a nuclear weapon.

"I think that the estimate would say that there may be the potential there to dissuade them (with economic sanctions), but right now they appear to be very, very determined," he said.