A Study on China-Indonesia Maritime Security Cooperation Against the Backdrop of U.S.-China Strategic Competition

China and Indonesia have expanded cooperation, which has become a key part of regional security interactions. Both sides share practical needs in areas such as the security of maritime channels, the governance of marine resources, cooperation in maritime law enforcement, and responses to non-traditional security threats. Furthermore, the alignment of the Belt and Road Initiative with Indonesia’s “Global Maritime Fulcrum” strategy provides an institutional foundation and room for development for this cooperation. From the analytical perspective of composite security theory, China-Indonesia maritime security cooperation is not the result of a single issue but rather a product of the combined effects of changes in the external strategic environment, the alignment of bilateral maritime strategies, and the rise of non-traditional maritime security threats. In practice, the two sides primarily advance cooperation through mechanisms such as political and diplomatic coordination, defense and security interactions, and law enforcement coordination. They have established a relatively stable foundation for cooperation in low-sensitivity areas such as maritime search and rescue, fisheries management, information sharing, and exchanges in marine science and technology and law enforcement. Overall, China-Indonesia maritime security cooperation is characterized by a distinct functional orientation, strong pragmatism, and pronounced stratification. This cooperation reduces risks and improves maritime governance. However, due to factors such as Indonesia’s orientation toward strategic autonomy, disputes over the Natuna Sea, and the intervention of external major powers, the depth of this cooperation still faces certain constraints.