This paper examines factors driving Indonesia’s and Vietnam’s approaches to the US-China strategic competition and implications to the East Asian security framework. The two countries are studied due to their significance in the region. Indonesia is known as a de facto leader of ASEAN due to its overwhelming population, territory, and historical claims. Meanwhile, Vietnam’s long coastline faces the South China Sea, a “strategic flashpoint” in the US-China strategic competition. The geopolitical significance, coupled with Hanoi’s ceaseless struggle against China’s influence, makes it a critical player in the regional security architecture. In this paper, the author posits Indonesia’s and Vietnam’s foreign policies under a combination of hedging theory and middle-power diplomacy. She contends that the hedging theory clarifies nuances between middle powers’ perspectives on powerhouses’ statecraft in their race for influence. At the same time, middle-power diplomacy yields an illuminating insight into how they respond to the great-power rivalry dynamics and contribute to regional security and stability. Therefore, by adopting both hedging and middle-power diplomacy theories, this paper is expected to comprehensively analyze Hanoi’s and Jakarta’s foreign policies vis-à-vis the US-China competition. Despite both highlighting strategic autonomy in their doctrines, Indonesia’s and Vietnam’s hedging strategies and middle-power diplomacy differ in practice. The author argues that how they hedge against the US-China competition and practice middle-power diplomacy is decided by their distinctive historical contexts, strategic environments, and resource availability.