WASHINGTON — Dozens of CIA informants in Iran were executed or imprisoned in the late 1980s or early 1990s after their secret communications with the agency were uncovered by the government, according to former CIA officials who discussed the episode after aspects of it were disclosed during a recent congressional hearing.
As many as 50 Iranian citizens on the CIA's payroll were "rolled up" in the failed operation, said the former officials, who described the events as a major setback in spying on a regime that remains one of the most difficult targets for U.S. intelligence.
The disclosures underscore the stakes confronting the CIA and its informants as the United States is under pressure to produce better intelligence on Iran and especially its nuclear activities. The Bush administration has indicated that preventing Iran from obtaining an atomic weapon will be a priority of the president's second term.
Like Iraq before the U.S. invasion in 2003, Iran is regarded as a "denied" territory by U.S. intelligence, meaning that the CIA has no official station inside the country and is largely dependent on recruiting sources outside the Islamic Republic's borders.
Details of the setback were first outlined Feb. 2 by former Pentagon advisor Richard N. Perle in testimony before the House Intelligence Committee. During a hearing on security threats, Perle was critical of U.S. intelligence capabilities and cited the crackdown on American sources in Iran as an example of the failures that have beset U.S. espionage in the Mideast.
Perle referred to the "terrible setback that we suffered in Iran a few years ago when in a display of unbelievable, careless management we put pressure on agents operating in Iran to report with greater frequency and didn't provide improved communications."
When the CIA's sources stepped up their reporting, "the Iranian intelligence authorities quickly saw the surge in traffic and, as I understand it, virtually our entire network in Iran was wiped out."
Former CIA officials familiar with the matter confirmed portions of Perle's account and provided additional details. But they said the incident occurred in the late 1980s or early 1990s, not "a few years ago," as Perle suggested, and that it was not clear that the informants were exposed because of any pressure from the agency to file reports more frequently.
The CIA declined to comment, but a U.S. intelligence official rejected Perle's criticism of the agency's record in the Mideast as ill-informed and outdated.
"Intelligence methods evolve constantly," said the official, who spoke on condition of anonymity. "Trying to use these things from the past to make assertions about the present is in this case ill-advised."
In a phone interview, Perle acknowledged that he had "a poor sense of time" concerning the events he described and was uncertain about details.
"I don't recall the details, or the mechanism by which the [Iranian agents] were communicating," Perle said. "What I was told was that our entire network was destroyed" and that as many as 40 of the informants were executed.
According to a former CIA official who served in the Mideast at the time, the Iranian informants were part of a network of spies that was run by CIA officers based at the agency's station in Frankfurt, Germany.
The Iranian spies communicated with the agency "via secret writing," the former official said, referring to messages printed in invisible ink on the backs of letters that were mailed out of the country. The spies received messages in the same fashion from a CIA officer in Frankfurt.
It is not clear what aroused the Iranian government's suspicion, "but all of the letters went to a handful of addresses in Germany," the former CIA official said, speaking on condition of anonymity.
"Once they had one agent and they recovered the letters that had come in to him and found out where he was sending his letters out, they quickly identified others who fit that profile," the former official said.
As many as 50 spies were exposed. They included members of Iran's military and were providing information on an array of activities, the former official said.
Iran was a major intelligence priority for the United States at the time. During the 1980s, the U.S. was supporting Iraq in its war against Iran. The regime in Tehran, the capital, had also launched its clandestine nuclear program by then, according to the International Atomic Energy Agency, the United Nations' nuclear watchdog group.
The CIA's Iran operation in Frankfurt was disbanded in the mid-1990s, and portions of it were relocated to Los Angeles, where the CIA still seeks to capitalize on Southern California's large Iranian population by cultivating sources who travel to the country or have relatives there.