This report has been professionally converted for accurate flowing-text e-book format reproduction. Since the turn of the 21st century, China has steadily expanded security cooperation in Southeast Asia, reflected in more frequent naval port calls and military exercises and in increased arms sales to states in the region. Why has China been pursuing closer security cooperation in Southeast Asia, and what factors influence the degree to which Southeast Asian states seek, accept, or reject security cooperation with China? This thesis finds that China is primarily motivated to improve security ties in Southeast Asia in order to establish regional preeminence and cement its status as a great power. Related and supporting Chinese objectives include using security cooperation to achieve the following: establish influence within key Southeast Asian states that can be wielded to serve Chinese interests, prevent encirclement by the United States or its allies, and assuage regional anxieties about perceived Chinese aggressiveness. This thesis also finds that factors influencing the degree to which Southeast Asian states seek, accept, or reject security cooperation with China include the level of U.S. security cooperation a state receives, an interest in diversification of security partnerships, the prevalence of illiberalism or human rights abuses, and the presence or absence of a territorial dispute with China.

This compilation includes a reproduction of the 2019 Worldwide Threat Assessment of the U.S. Intelligence Community.

I. Introduction * A. Major Research Question And Main Findings * B. Significance Of The Research Question * C. Literature Review * 1. Deepening Security Cooperation Between China And Southeast Asia * 2. Chinese Objectives For Security Cooperation In Southeast Asia * 3. Factors Influencing Southeast Asian Receptiveness To Chinese Security Cooperation * D. Potential Explanations And Hypotheses * E. Research Design * F. Thesis Overview * II. Sino-Southeast Asian Security Cooperation: The Chinese Side Of The Equation * A. Introduction * B. Scale Of Chinese Security Cooperation In Southeast Asia * 1. Naval Port Calls * 2. Military Exercises * 3. Arms Sales * C. Chinese Objectives For Security Cooperation In Southeast Asia * 1. Establish Regional Preeminence And Status As A Great Power * 2. Establish Influence In Key States That Can Be Used To Serve Chinese Interests * 3. Undercut U.S. Encirclement And Dominance In The Region * 4. Assuage Perceptions Of Chinese Aggressiveness * 5. Secondary Objectives Driving Chinese Security Cooperation In Southeast Asia * D. Factors Limiting Sino-Southeast Asian Security Cooperation * E. Conclusion * III. Establishing The Spectrum Of Southeast Asian Security Cooperation With China And Selecting Case Countries * A. Introduction * B. Range Of Southeast Asian Security Cooperation With China * 1. Naval Port Calls * 2. Military Exercises * 3. Arms Sales * C. Selection Of Representative Countries For Case Study * D. Conclusion * IV. Sino-Southeast Asian Security Cooperation: Thailand And The Philippines * A. Introduction * B. Factors Influencing Thai And The Philippine Rates Of Security Cooperation With China * 1. Decreased U.S. Security Cooperation * 2. Diversification * 3. Illiberal Political Transitions And Human Rights Abuses * 4. Territorial Disputes * C. U.S. Comparative Advantage In Thailand And The Philippines * D. Conclusion * V. Conclusion * A. Summary Of Findings * B. Outlook * C. Policy Recommendations