China killed or imprisoned 18-20 CIA sources
A massive intelligence breach occurred from 2010 to 2012 and it allowed the Chinese government to help clean out its ranks of CIA spies.
The Chinese killed at least a dozen CIA sources fro 2010-2012 and imprisoned a half-dozen more, according to the New York Times. One was shot in front of his colleagues in the courtyard of a government building as an example.
Investigators still aren't sure whether a spy within the CIA betrayed the sources or if the Chinese hacked the CIA's systems.
Since 2013, the US has been trying to rebuild its spy network there.
