Between 2010-2012, the Chinese government murdered or imprisoned 18 to 20 CIA agents after it demolished America’s spying operations within the country. The CIA has been investigating how this happened, whether a mole leaked information to Beijing or the Chinese managed to break our codes. The New York Times reported:

Assessing the fallout from an exposed spy operation can be difficult, but the episode was considered particularly damaging. The number of American assets lost in China, officials said, rivaled those lost in the Soviet Union and Russia during the betrayals of both Aldrich Ames and Robert Hanssen, formerly of the C.I.A. and the F.B.I., who divulged intelligence operations to Moscow for years.

The previously unreported episode shows how successful the Chinese were in disrupting American spying efforts and stealing secrets years before a well-publicized breach in 2015 gave Beijing access to thousands of government personnel records, including intelligence contractors. The C.I.A. considers spying in China one of its top priorities, but the country’s extensive security apparatus makes it exceptionally hard for Western spy services to develop sources there.

Information Stopped Coming in From China

American officials noticed problems toward the end of 2010 after the CIA enjoyed some of the best intel it has received since it had recruited “sources deep inside the bureaucracy in Beijing.” Suspicions became reality after 2011 began: “the flow of information began to dry up” while those people they picked up began to disappear.

The FBI and CIA joined forces to form an investigation, code named Honey Badger, to find out what happened. After all, the Chinese investigated everyone at the US Embassy in Beijing. Yes, EVERYONE, even those at the top tier.

At first, no one wanted to believe within the CIA betrayed the agents, but too much evidence has forces agents to reach that conclusion. The New York Times continued:

The mole hunt eventually zeroed in on a former agency operative who had worked in the C.I.A.’s division overseeing China, believing he was most likely responsible for the crippling disclosures. But efforts to gather enough evidence to arrest him failed, and he is now living in another Asian country, current and former officials said.

There was good reason to suspect an insider, some former officials say. Around that time, Chinese spies compromised National Security Agency surveillance in Taiwan — an island Beijing claims is part of China — by infiltrating Taiwanese intelligence, an American partner, according to two former officials. And the C.I.A. had discovered Chinese operatives in the agency’s hiring pipeline, according to officials and court documents.

Possible Suspect

The investigators began to cross off the suspects on a list until they reached the name of a Chinese-American. This man, left unnamed by the Times, “had left the C.I.A. shortly before the intelligence losses began.” A few thought “he had become disgruntled” and chose to spy for Beijing. One person told the Times that “the man had access to the identities of C.I.A. informants and fit all the indicators on a matrix used to identify espionage threats.” Here’s why the agents chose him:

After leaving the C.I.A., the man decided to remain in Asia with his family and pursue a business opportunity, which some officials suspect that Chinese intelligence agents had arranged.

Officials said the F.B.I. and the C.I.A. lured the man back to the United States around 2012 with a ruse about a possible contract with the agency, an arrangement common among former officers. Agents questioned the man, asking why he had decided to stay in Asia, concerned that he possessed a number of secrets that would be valuable to the Chinese. It’s not clear whether agents confronted the man about whether he had spied for China.

The man defended his reasons for living in Asia and did not admit any wrongdoing, an official said. He then returned to Asia.

Other Possibilities?

But not all agents have accepted the mole theory. Instead, some agents think sloppiness caused the Chinese to figure out the spy network:

Some F.B.I. agents became convinced that C.I.A. handlers in Beijing too often traveled the same routes to the same meeting points, which would have helped China’s vast surveillance network identify the spies in its midst.

Some officers met their sources at a restaurant where Chinese agents had planted listening devices, former officials said, and even the waiters worked for Chinese intelligence.

This carelessness, coupled with the possibility that the Chinese had hacked the covert communications channel, would explain many, if not all, of the disappearances and deaths, some former officials said. Some in the agency, particularly those who had helped build the spy network, resisted this theory and believed they had been caught in the middle of a turf war within the C.I.A.

Damage Done

The agents put a stop to the Chinese picking off America’s sources, but it was too late. The Chinese damaged the spy network to the point where the CIA could not put it back together.

The process to rebuild became too expensive and those involved did not have the heart to put more effort into the project, including the man who once led the East Asia Division:

A former intelligence official said the former chief was particularly bitter because he had worked with the suspected mole and recruited some of the spies in China who were ultimately executed.

China has been particularly aggressive in its espionage in recent years, beyond the breach of the Office of Personnel Management records in 2015, American officials said. Last year, an F.B.I. employee pleaded guilty to acting as a Chinese agent for years, passing sensitive technology information to Beijing in exchange for cash, lavish hotel rooms during foreign travel and prostitutes.

Traitors Within: Spies Who Sold Out America