Although Chinas intelligence activities may not have been well documented they can be traced back to the ancient writings of Sun Tzu and espionage has been a characteristic of Chinese domestic politics and international relations ever since. The Peoples Republic of China has long engaged in espionage but relatively little is known about Chinese techniques methodology personnel and organizations in comparison with what the West has learned about other more conventional intelligence agencies that conduct operations across the world. Whereas most intelligence services have suffered damaging defections the number of Ministry of State Security professionals who have switched sides is relatively small further limiting outside knowledge.