Over the past decade, the United States has been the most significant “Other” in China’s national security discourse—an “Other” that has evolved from being a regional rival to becoming a global competitor. China’s national security documents, particularly China’s Military Strategy (2015) and China’s National Defense in the New Era (2019), provide a clear depiction of this transformation. Drawing on the constructivist approach and Alexander Wendt’s concept of the “Other,” this study analyzes the representation of the United States in these documents. The central question is how China represented the United States between 2014 and 2022, and what impact this representation had on its foreign relations. The findings reveal that China has predominantly portrayed the United States as a “rival Other” in its national security documents, a rivalry that first emerged at the regional level in areas such as East Asian security, the Taiwan issue, and the South China Sea disputes, and later expanded to the global stage through issues such as the trade war, advanced technologies, geopolitical competition, and the international order. Accordingly, the representation of the United States as a “rival Other” has not only shaped China’s defensive and security orientations in its immediate environment but also reinforced its strategies on the global stage, including deepening cooperation with Russia, expanding engagement in international institutions, and seeking to redefine the international order. Methodologically, this study employs a qualitative approach and content analysis of official documents.