Annual Report to Congress: Military and Security Developments Involving the People's Republic of China, 2013 [open pdf - 3MB]
"The People's Republic of China (PRC) continues to pursue a long-term, comprehensive military modernization program designed to improve the capacity of its armed forces to fight and win short-duration, high-intensity regional military conflict. Preparing for potential conflict in the Taiwan Strait appears to remain the principal focus and primary driver of China's military investment. However, as China's interests have grown and as it has gained greater influence in the international system, its military modernization has also become increasingly focused on investments in military capabilities to conduct a wider range of missions beyond its immediate territorial concerns, including counter-piracy, peacekeeping, humanitarian assistance/disaster relief, and regional military operations. Some of these missions and capabilities can address international security challenges, while others could serve more narrowly-defined PRC interests and objectives, including advancing territorial claims and building influence abroad."
U.S. Department of Defense: http://www.defense.gov/