Existing research on nuclear deterrence mainly focuses on mature nuclear arsenals, with few studies addressing the deterrent power of nascent nuclear arsenals. This paper argues that the uncertainty surrounding the doctrines guiding the use of new nuclear arsenals effectively deters potential adversaries from considering or initiating conventional attacks. Utilizing a qualitative approach, this research conducts a single case study on China's nascent nuclear arsenal and its role in deterring U.S. aggressive intentions. The stark contrasts between the U.S. attitude towards non-nuclear China during the Korean War and the Taiwan Strait Crisis and its mindset towards nuclear China during the Nixon administration highlight the deterrence effect of nascent nuclear arsenals. This case study contributes to a deeper understanding of how nascent nuclear capabilities can shape international relations and complements existing theories by illustrating the deterrent power of nascent nuclear arsenals.