07/16/2009 05:12 am ET | Updated May 25, 2011

Reliable Sources: Raising the Stakes of the Interrogation Debate

The principal value of intelligence is to provide reliable information to policymakers on a rival's true plans and intentions. The CIA's ability to provide such a decision advantage to U.S. policymakers depends on its ability to acquire reliable information from clandestine sources, or spies.

While there's no doubt that good intelligence can help keep us safe, intelligence officers and policy makers must grapple with the reliability of information, and -- just as importantly -- with how it is obtained.

If only it were so easy. Espionage is an art form, not a science. One never masters the art of intelligence, but is ever humbled by its elusive and myriad forms of expression. This is true because espionage is rooted in the human factor, fueled by the limitless boundaries of human emotions, motivations, and vulnerabilities.

The maddening reality is therefore that intelligence work is conducted in a gray world of Heisenberg-like probabilities, not of certainties. Consumers of intelligence must become accustomed to this reality and remember that there is no easy formula for guaranteeing the reliability of sources, however rock solid they may seem.

Intelligence professionals learn this lesson in the school of hard knocks.

In the late 1980's, U.S. intelligence scored a coup when a senior officer inside KGB counterintelligence volunteered his services to the CIA in Moscow. This agent was in a position to provide information on CIA activity in the Soviet Union. In spite of his access, however, his information was of an uneven quality. Over the next two years, a debate raged within the agency. Was he a reliable source, or an agent provocateur who had been sent by the Russians to deceive the U.S? Opinions were strongly divided. The stakes were high: if this reporting was reliable, it meant the CIA had the upper hand over the KGB, but if this spy was double crossing the CIA, it implied there must be a Russian mole within the ranks of the agency. Only the passage of time revealed the truth of the matter. The CIA learned the agent had been a Russian double agent from the start.

Fifteen years later, the agency faced a similar quandary concerning the reliability of one of its high profile sources. A German agent code named "Curveball" provided detailed information confirming the existence of an Iraqi biological weapons program. Yet, within operational ranks in the agency, there were vague doubts over Curveball's bona fides. There were questions about his access and motivation for providing the information. Was he a reliable source? The CIA requested access to debrief and vet the source independently in an effort to resolve concerns. The Germans refused. Ultimately, Curveball was revealed to have fabricated the information he provided. CIA and German intelligence share responsibility for failing to establish Curveball's reliability, especially since independent sources were unable to corroborate his explosive reporting.

The capture of senior al Qaeda terrorists put the agency's ability to apply old lessons concerning the reliability of its sources to the ultimate test. It was understood that these "sources" were inherently unreliable. They had no motivation to cooperate with the CIA. They actively resisted providing useful information. With no illusions as to their proclivity to deceive and misinform, the CIA's ability to establish the reliability of information from detainees depended entirely on corroborating their reporting. All information was considered suspect until it could be verified, no matter how it was obtained.

Through such a continuous vetting process, there is no question that reporting obtained through interrogation proved to be valuable, including the use of enhanced measures. Taken together, detainee reporting represents a body of invaluable information on the al Qaeda organization, its connections, and activities. Certainly, detainees provided a mix of fact and fiction. However, effective action was taken on the basis of information obtained through interrogation. Much information was confirmed through meticulous cross checking of facts with other reporting. Indeed, the strongest correlation in establishing the reliability of information was not based on the methods used to acquire it, but on the quality of the debriefing and expertise of the interrogator.

This experience is consistent with broader practice. The CIA is the beneficiary of information from all kinds of sources with all sorts of motivations. Much flows in from other countries, especially liaison reporting related to terrorism and threats against American interests. Typically, methods of acquisition are not known, nor are details about sources. All information must thus be weighed against other relevant reporting and reviewed by substantive experts. In the end, the intelligence officer's professional intuition and instinct are often decisive in properly handling and disseminating information.

Taking the full body of intelligence into account, the record will reflect that enhanced means of interrogation can yield valuable information.

If this is true, it raises the stakes of the current debate over how far we are willing to go in order to obtain information through interrogation. Protecting our country from terrorist attacks by obtaining reliable intelligence is essential. But it is also essential to assure U.S. moral authority by acting in a manner that is consistent with our high ideals.

Rolf Mowatt-Larssen is a senior fellow at Harvard Kennedy School's Belfer Center for Science and International Affairs. He is a former director of the Office of Intelligence and Counterintelligence at the U.S. Department of Energy and former head of the Central Intelligence Agency's WMD and terrorism efforts.