China has declared some of its history as too hot to handle. The national police were recently ordered to make it clear to people in their jurisdictions that no anti-Japanese demonstrations, on the 60th anniversary of the end of World War II, or September 3rd (the official World War II victory day in China), would be tolerated. The government fears that the demonstrations against the hated Japanese would turn into violence against the hated Chinese bureaucracy. The government knows there is a lot of popular unrest over corruption and poor administration. They don't want a lot of large demonstrations that could quickly switch targets.
Taiwanese officials are asking for Japan and the United States to join with Taiwan in an alliance to deal with growing Chinese military power. Both China and Taiwan have long supported energetic, and successful, efforts to spy on each other. They catch each others spies all the time. As a result, there are not a lot of secrets on either side of the Taiwan straits.