Although the Pentagon warns that WikiLeaks could have blood on its hands for publishing classified U.S. war documents that name Afghan sources, history shows that similar disclosures have not always led to violence.
It is difficult to find clear-cut examples of the public exposure of informants leading to their deaths, although there are documented cases of a deadly ending to the secret unmasking of foreign agents. Recall the Aldrich Ames espionage case of the early 1990s: The now-jailed CIA turncoat ratted on Soviet informants and at least nine of them were believed executed by the KGB.
The WikiLeaks leak is unrivaled in its scope, but so far there is no evidence that any Afghans named in the leaked documents as defectors or informants from the Taliban insurgency have been harmed in retaliation.
Some private analysts, in fact, think the danger has been overstated.
"I am underwhelmed by this argument. The Pentagon is hyping," says John Prados, a military and intelligence historian who works for the anti-secrecy National Security Archive. He said in an interview that relatively few names have surfaced and it's not clear whether their present circumstances leave them in jeopardy.
Donald P. Gregg, a retired CIA officer and former U.S. ambassador to South Korea, said in an e-mail exchange that the Pentagon's expressions of concern have merit in this case. But he also said his own experience showed that being unmasked as a spy is not always deadly.
"I was named and publicly denounced as a covert CIA officer by East Germany in 1958, and no one, to my knowledge, ever tried to assassinate me," Gregg said.
The Taliban itself, however, has said it is scouring the tens of thousands of leaked documents -- mostly raw military intelligence reports -- for names of Afghans who sided with the U.S. and NATO against the insurgency. Rep. Jane Harman, a California Democrat, said the leak amounted to handing the Taliban an "enemies list."
"We know the Taliban are harsh and cruel in their treatment of disfavored persons, so it is extremely serious," said Steven Aftergood, an anti-secrecy advocate who writes the Secrecy News blog. "WikiLeaks is giving 'leaks' a bad name by putting people in jeopardy."
Rep. Rush D. Holt, D-N.J., who opposes the U.S. war strategy in Afghanistan, said last week that some of the leaked documents could result in "real harm to real people" -- particularly defectors from the Taliban who were interrogated and then released.
"We may presume that after they are released from custody they and their families could be in danger of assassination by other insurgents," Holt wrote in a statement Aug. 10.
In addition to any immediate security risk to Afghans, administration officials say the leak undermines the credibility of U.S. promises to protect the identity of informants. That in turn could hamper U.S. intelligence efforts in the future.
One of the most spectacular cases of exposing foreign agents was Philip Agee's 1975 book, "Inside the Company: CIA Diary."
As a former CIA officer, Agee identified in his book more than 200 agency officers, front companies and foreign agents working for the U.S. abroad. He wrote that this was "one way to neutralize the CIA's support to repression."
He is sometimes accused of responsibility in the death of Richard Welch, the CIA station chief in Athens who was assassinated in 1975 by a Greek terrorist group. Agee and his friends say the accusation is groundless, noting that Welch was not named in Agee's book and that Welch's agency link was publicly known.
His and subsequent exposure of agents led Congress to pass the Intelligence Identities Protection Act of 1982, making it a crime to intentionally reveal the identity of a covert intelligence officer.
Among the earliest expressions of outrage at the Afghan war leaks was from Adm. Mike Mullen, chairman of the Joint Chiefs of Staff. He said he was appalled at the judgment of WikiLeaks.org website found Julian Assange and the unidentified provider of the secret documents.
"The truth is they might already have on their hands the blood of some young soldier or that of an Afghan family," Mullen told a Pentagon news conference four days after the leak.
Defense Secretary Robert Gates said the U.S. has a moral responsibility to "those who have worked with and put their trust in us in the past, who now may be targeted for retribution."
Last week during a visit aboard a Navy warship in San Diego, Gates told a sailor who asked about the seriousness of the WikiLeaks case: "We don't have specific information of an Afghan being killed yet because of them. But I put emphasis on the word 'yet.'"
Gates' press secretary, Geoff Morrell, said the Pentagon is relaying names of Afghans exposed in the documents to U.S. military commanders in Afghanistan so they can "safeguard those people." It's not clear what steps the U.S. has taken to accomplish this.
The issue could be magnified by an expected WikiLeaks posting soon of thousands of additional leaked documents. Administration officials have said those could be even more compromising.
The vulnerability of locals who work with U.S. forces -- openly or secretly -- is not just an issue in Afghanistan. A bipartisan group of congressmen and senators called on the Obama administration last week to urgently expand efforts to resettle Iraqis who have worked for U.S. agencies in Iraq, even saying an airlift should be considered. Many of the Iraqis will be targeted for assassination by al-Qaida in Iraq, they said.
"Providing support for our Iraqi allies will advance U.S. national security interests around the world, particularly in Afghanistan, by sending a message that foreign nationals who support our work abroad can expect some measure of protection," the lawmakers wrote to Secretary of State Hillary Rodham Clinton.