1951

In order to open a second front in the Korean War, CIA officers decided to rely upon a second plan. CIA operators were fearful of Mao Zedong's entry into the war and estimated that a substantial amount of Kuomintang Nationalist guerillas were available to work with the agency. They also estimated that Muslim horsemen led by Ma Bufang would be willing to launch attacks against China in its western regions. When both of these efforts proved to be overly projected in terms of success and strategic actualities, the U.S., convinced that a third force was available within China, decided to invest resources into securing such a force to its efforts. In order to facilitate resistance against China's involvement in Korea, the CIA invested over $100 million in buying weapons that would be used by "third force" guerillas in China. The Agency scarcely could find any anti-Mao sentiment within their contacts, however, with the only signs of life being a group of refugees in Okinawa, invariably proven to be a group more interested in obtaining their own goals than in truly assisting the United States.^[4]

Eventually, the CIA declassified its records and admitted the failures of the Third Force strategy.^[5] The list illuminated a quick study on insurgency failures. According to the documents, the CIA began dropping small guerilla units into China, the first Third Force team having been deployed in April, 1952. All four members of the team were never heard from again. The second Third Force team was made up of five ethnic Chinese agents, and dropped into the Jilin region of Manchuria in mid-July 1952. The team eventually reported contact with local rebel leaders. The team was, unbeknownst to the CIA, captured and turned by the Chinese, setting up the ensuing trap. The CIA responded by sending in a rescue unit, only to have its planes shot down and its principal agents assigned to the mission, Jack Downey and Dick Fecteau, arrested. Both men were subsequently sentenced to prison sentences in China. Beijing later boasted of the insurgency failures of their United States counterparts. At that point, the CIA had dropped 212 agents into China, resulting in 101 agents killed and 111 captured.^[5][6][7] Michael D. Coe, who had been recruited by the CIA and worked within the agency during the Third Force events, stated that the CIA "had been sold a bill of goods by the Nationalists - that there was a huge force of resistance inside of China. We were barking up the wrong tree. The whole operation was a waste of time."^[8]

1959

In 1959, China learned that United States spy planes were carrying out missions throughout China, including above Beijing.^[9]: 43 Anti-air brigades were able to shoot down a few United States spy planes in the early 1960s, but their overall inefficacy demonstrated the limitations of the People's Liberation Army in responding to aircraft incursions.^[9]: 43

The CIA provided the Tibetan Chushi Gangdrug Tenshung Danglang Mak group with material assistance and aid, including arms and ammunition, as well as training to members of Chushi Gangdruk and other Tibetan guerrilla groups at Camp Hale.

2000s

In 2001, a presidential plane built in the United States for Chinese President Jiang Zemin was found to have listening devices installed.^[10]: 53 Chinese authorities located at least 20 devices, including one in the headboard of the presidential bed.^[11] The listening devices were capable of being operated via satellite.^[11]

2010

According to an investigation by The New York Times, the government of the PRC was able to either kill or imprison 18 to 20 CIA sources from 2010 to 2012; an article in Foreign Policy cited a higher number, putting the number of sources killed at at least 30.^[12][13] A joint CIA and FBI counterintelligence operation set up to investigate the intelligence failure advanced three different theories^[13][14] as to why the spy network was dismantled: (1) there was a mole within the CIA, (2) "sloppy tradecraft" and (3) PRC intelligence agents had hacked the covert system the CIA used to communicate with its foreign sources. The New York Times said that the debate over the cause remained unsolved while a former American intelligence official cited by Foreign Policy said investigators concluded that it was caused by a "confluence and combination of events."^[12] In January 2018, a former CIA officer named Jerry Chun Shing Lee was arrested and would eventually plead guilty^[15][16] on suspicion of helping dismantle the network^[14] while the Foreign Policy article ascribed, notwithstanding the arrest, the failure to the ability of the PRC intelligence agencies to penetrate the CIA's communication system.^[12]

Sun Bo, a general manager of the China Shipbuilding Industry Corporation, was investigated for corruption and supplying classified information to the CIA, including technical specifications of the Chinese aircraft carrier Liaoning, according to Asia Times.^[17] Sun Bo was sentenced to 12 years in prison on July 4, 2019.^[18]

A December 2020 article by Zach Dorfman in Foreign Policy suggested that decades of corruption inside of the Chinese Communist Party (CCP) had created vulnerabilities exploited by outside intelligence agencies, particularly the CIA. CCP purges under the guise of anti-corruption were at least partially motivated by counterintelligence concerns.^[19]

2021

In October 2021, The New York Times citing a leaked CIA cable, reported that the CIA had admitted to have lost a "troubling number of informants" recruited from countries including China in recent years, with informants being killed, captured or compromised. The leaked cable comes amid China's recent efforts in hunting down CIA sources to turn them into double agents.^[20] The memo also mentions a "breach of the classified communications system" that led to spy networks in China being caught and that some officials believe that treasonous US intelligence officers may be the culprits responsible for the arrests and execution of CIA spies.^[20]