The CIA considers Israel its No. 1 counterintelligence threat in the agency's Near East Division, the group that oversees spying across the Middle East, according to current and former officials. Counterintelligence is the art of protecting national secrets from spies. This means the CIA believes that U.S. national secrets are safer from other Middle Eastern governments than from Israel.
Israel employs highly sophisticated, professional spy services that rival American agencies in technical capability and recruiting human sources. Unlike Iran or Syria, for example, Israel as a steadfast U.S. ally enjoys access to the highest levels of the U.S. government in military and intelligence circles.
...Israel is not America's closest ally, at least when it comes to whom Washington trusts with the most sensitive national security information. That distinction belongs to a group of nations known informally as the "Five Eyes." Under that umbrella, the United States, Britain, Australia, Canada and New Zealand agree to share intelligence and not to spy on one another. Often, U.S. intelligence officers work directly alongside counterparts from these countries to handle highly classified information not shared with anyone else.
Israel is part of by a second-tier relationship known by another informal name, "Friends on Friends." It comes from the phrase "Friends don't spy on friends," and the arrangement dates back decades. But Israel's foreign intelligence service, the Mossad, and its FBI equivalent, the Shin Bet, both considered among the best in the world, have been suspected of recruiting U.S. officials and trying to steal American secrets.
...During the Bush administration, the CIA ranked some of the world's intelligence agencies in order of their willingness to help in the U.S.-led fight against terrorism. One former U.S. intelligence official who saw the completed list said Israel, which hadn't been directly targeted in attacks by al-Qaida, fell below Libya, which recently had agreed to abandon its nuclear weapons program.
...Some CIA officials still bristle over the disappearance of a Syrian scientist who during the Bush administration was the CIA's only spy inside Syria's military program to develop chemical and biological weapons. The scientist was providing the agency with extraordinary information about pathogens used in the program, former U.S. officials said about the previously unknown intelligence operation.
At the time, there was pressure to share information about weapons of mass destruction, and the CIA provided its intelligence to Israel. A former official with direct knowledge of the case said details about Syria's program were published in the media. Although the CIA never formally concluded that Israel was responsible, CIA officials complained to Israel about their belief that Israelis were leaking the information to pressure Syria to abandon the program. The Syrians pieced together who had access to the sensitive information and eventually identified the scientist as a traitor.
Before he disappeared and was presumed killed, the scientist told his CIA handler that Syrian Military Intelligence was focusing on him.