Around that time, Chinese spies compromised National Security Agency surveillance in Taiwan — an island Beijing claims<br />is part of China — by infiltrating Taiwanese intelligence, an American partner, according to two former officials.<br />All told, the Chinese killed or imprisoned 18 to 20 of the C. I.A.’s sources in China, according to two<br />former senior American officials, effectively unraveling a network that had taken years to build.<br />Mr. Kelton often mentioned Mr. Kelley’s mistreatment in meetings during the China episode, former colleagues say,<br />and said he would not accuse someone without ironclad evidence.<br />The number of American assets lost in China, officials said, rivaled those lost in the Soviet Union<br />and Russia during the betrayals of both Aldrich Ames and Robert Hanssen, formerly of the C. I.A.<br />At the time, the quality of the C. I.A.’s information about the inner workings of the Chinese government was the best it<br />had been for years, the result of recruiting sources deep inside the bureaucracy in Beijing, four former officials said.<br />From the final weeks of 2010 through the end of 2012, according to former American<br />officials, the Chinese killed at least a dozen of the C. I.A.’s sources.<br />spying operations in the country starting in 2010, killing or imprisoning more than a dozen sources over two years<br />and crippling intelligence gathering there for years afterward.
