China is engaged in a campaign to take control of large portions of the South China Sea, including significant portions of the exclusive economic zones of other countries, by conducting various gray zone operations that have allowed China to exert control over the region while avoiding a conventional military response from the United States and its allies and partners. China's use of various gray zone tactics to assert its territorial claims and achieve its political agenda includes maritime aggression, cyber operations, economic coercion, and online propaganda. As a matter of policy, China views these actions as a continuation of politics rather than warfare, and China's efforts are purposefully designed to be below the threshold of war. The authors identify approaches for the U.S. Indo-Pacific Command (USINDOPACOM) and other elements of the U.S. military to counter and deter Chinese maritime gray zone operations. The authors focus on approaches that encompass presence operations, transparency initiatives that publicize malign Chinese behaviors, efforts to spur U.S. partners and allies to help counter China's gray zone effort, and the use of non-lethal weapons to directly confront and deter China's aggressive behaviors. To conduct this study, the authors conducted an in-depth literature review of China's maritime gray zone operations, hosted an online forum of gray zone and China experts to discuss potential counter strategies, and conducted interviews with more than 45 experts from the USINDOPACOM and its subordinate service components and others in the defense community.

The United States is entering a new era of great-power competition with China. In this era of competition, the United States is working to acquire the high-end weaponry that is necessary to deter China from pursuing kinetic conflict. However, the U.S. Department of Defense faces an immediate challenge: the gray zone, a space between peace and war in which China operates to achieve its political objectives. Using brute force tactics, such as island building, ship ramming, and water cannons, China seeks to control the South China Sea and East China Sea to undermine regional political autonomy and U.S. security commitments. This report aims to provide U.S. decisionmakers and a general audience with an understanding of the types of actions that countries in the region are taking to counter China's gray-zone efforts, the associated challenges, and their limitations. The countries of Southeast and East Asia — particularly Indonesia, Japan, Malaysia, the Philippines, Taiwan, and Vietnam — are the primary targets of China's gray-zone actions; therefore, these countries will be the key drivers in executing a broader counter-China gray-zone strategy. In this report, the authors intend to provide U.S. decisionmakers with the necessary background information to synchronize U.S. responses in support of enabling regional responses.