For years the Russian KGB, the CIA and other espionage organizations have tried to fathom the enigmatic course of life in China by monitoring provincial radio broadcasts, intercepting military messages and occasionally recruiting contacts within the People's Republic. Not surprisingly, the best China spies are the Chinese themselves. Agents of Taiwan's intelligence network in past years have provided the most sensational and intimate glimpses into the murky world of Peking politics.
In recent weeks Taiwan has even been willing to advertise its network of loyalists and informers on China's mainland. Breaking with...