Never had the U.S. government disclosed as much sensitive, recent intelligence as Secretary of State Colin L. Powell did yesterday when he released surreptitiously intercepted calls between Iraqi officials and information supplied by Iraqi informants apparently close to Saddam Hussein.

Beyond the extraordinary array of U.S. intelligence capabilities put on display for the U.N. Security Council -- signals intercepts, satellite imagery, reports from captives and in-country agents -- 10 foreign intelligence services, both European and Middle Eastern, agreed to allow the United States to disclose classified information they had collected on Iraq.

"They frankly revealed more intelligence capabilities and assessment, and sources and methods than I've ever seen," said Sen. Pat Roberts (R-Kan.), chairman of the Senate intelligence committee.

The U.S. intelligence community has historically been fiercely protective of its sources and methods, and various laws make releasing classified information a crime under certain circumstances. Powell's presentation before the Security Council was vetted closely beforehand, but its disclosures indicate how strongly the Bush administration felt the need to state its case for attacking Iraq.

The extent of the technical disclosures stunned former intelligence officials and lawmakers. But the more significant revelations were the secretary's understated references to "human intelligence," "foreign intelligence services" and just "sources," which analysts said referred to Iraqis inside Iraq who are feeding information to foreign intelligence services or, possibly, the United States.

"That suggests, in one way or the other, we're operating inside Iraq," said Thomas Powers, a noted author specializing in intelligence issues.

"Over time, our intelligence on the ground has gotten better," one intelligence official said. The official added that Iraqi military officers have made themselves more accessible as they have seen the seriousness of the U.S. military buildup and want to end up on the winning side.

Some information supplied by Iraqis came from defectors whose locations have never been disclosed. Robert Baer, a former CIA case officer, cautioned that it is impossible to judge the credibility of human sources from Powell's presentation.

"I don't trust it without the whole context," said Baer, who recruited foreign agents for the CIA in the 1990s. "In the absence of that, you have to just trust the administration . . . They have all the marbles." If the human intelligence is so good, he added, why haven't the U.N. inspectors found a mobile chemical laboratory?

Taken in total, said Powers, the intelligence presentation tells the Iraqis: "If they talk, we're going to hear it; if they move, we'll pick them up" on imaging devices.

Yesterday was the first time in recent memory that the United States released the actual audio of intercepts. The last time the government revealed extensive intercepted communications was in 1996, when Madeleine K. Albright, then the U.S. ambassador to the United Nations, released transcriptions of conversations between Cuban fighter pilots who shot down two small planes owned by Cuban exiles that were flying north of Cuba.

Intelligence officials consider intercepted communications so sensitive that lawmakers have enacted a law that makes unauthorized disclosure of an intercept a crime, whether or not the disclosure harmed or was meant to harm U.S. national security, said Jeffrey Smith, former CIA general counsel.

While it is no surprise that the United States has extensive imagery capabilities and is monitoring suspected Iraqi weapons sites, some satellite photos Powell presented yesterday showed a level of detail rarely seen in public. For example, the description of chemical bunkers included dated photos showing security staff and decontamination vehicles -- to analysts, a telltale sign of ongoing work.

Releasing such detail "was a tough call," one knowledgeable U.S. official said. It could "help Iraq's denial and deception" toward inspectors in the future.

U.S. intelligence officials routinely contend that releasing classified information, even after decades, can compromise sources and reveal just how they collect secrets. For months, administration officials have used this argument to justify their refusal to provide fresh evidence against Iraq.

In explaining how such sensitive information was disclosed now, U.S. officials said a half-dozen intelligence officials participated in a "sources and methods review committee." It assessed and rated the risk of disclosing each classified bit of information to future collection efforts, military operations and the safety of informants.

Parts of Powell's speech were deleted or reworded, U.S. officials said, when the risk was deemed too great.

"It was done very carefully to ensure the price we paid wasn't too high," said one senior U.S. official involved in the process. Still, U.S. officials acknowledged that some communications circuits would inevitably be lost as a result of yesterday's presentation.

Director of Central Intelligence George J. Tenet, who sat behind Powell as the intelligence community's stamp of approval, had the final say on declassifying the intelligence presented yesterday.

Senior administration officials said the CIA permitted the release of only a small amount of the intelligence it possesses.

For an agency that still maintains national security would be damaged if it released its 1947 total budget figure, yesterday's disclosure must have been "a security officer's nightmare, but clearly the right thing to do," said Steven Aftergood, director of the Federation of American Scientists' Project on Government Secrecy and a CIA watchdog.

After speaking to the Security Council, Secretary of State Colin L. Powell, right, talks to CIA Director George J. Tenet. The extent of the speech's technical disclosures, such as signals intercepts and satellite imagery, surprised former intelligence officials and lawmakers.