Can Indo-Pacific Powers Deter China Without the US?

The U.S. decision to revert U.S. Indo-Pacific Command to just Pacific Command has fueled concerns among regional allies about Washington's waning interest in the Asia-Pacific. This shift, a reversal from its 2018 "Free and Open Indo-Pacific" strategy, coupled with China's economic rise, amplifies the potential for Chinese regional hegemony. In response, regional powers are bolstering their independent diplomatic and security strategies. Indian Prime Minister Narendra Modi recently concluded tours of Indonesia, Australia, and New Zealand. South Korean President Lee Jae-myung visited India and Vietnam, while Japanese Prime Minister Takaichi Sanae engaged in back-to-back visits to Southeast Asia, Australia, South Korea, and India. This flurry of diplomatic activity highlights how these nations are seeking to deter China even without the United States. Collectively, Japan, South Korea, India, Australia, and Indonesia can achieve "deterrence by denial" at sea. These five nations straddle critical sea lanes like the First Island Chain and the Malacca, Sunda, and Lombok straits, through which a significant portion of China's energy imports pass. Japan is enhancing its counterstrike capabilities with a defense budget reaching 2% of GDP. South Korea boasts a strong defense industry and plans to increase its defense spending. India can tie down Chinese forces on its Himalayan frontier and export BrahMos missiles to Jakarta. However, deterring a major war remains challenging without U.S. extended nuclear deterrence, comprehensive mutual defense obligations, unified command structures, and shared war plans. South Korean forces remain focused on Pyongyang, and the Japan-South Korea relationship is still hampered by historical issues and political sensitivities. In this context, cooperation among regional powers should focus on four key areas: enhancing maritime domain awareness, expanding logistics and access, co-producing defense industries, and building collective resilience against economic coercion. With China leveraging "economic coercion" as a primary battleground, securing independence in critical mineral supply chains is an urgent priority. To collectively deter China, these countries must develop stronger institutional frameworks bilaterally and multilaterally. While the strategic defense coordination between Australia and Japan is progressing, cooperation with India, South Korea, and Indonesia faces hurdles due to differing threat perceptions, historical issues, and political vulnerabilities. Indonesia, for instance, has not identified a specific threat and continues to strengthen trade with Beijing. These nations must move beyond individual risk hedging to form a meaningful collective deterrent.