As China’s power in the international system increases, its strategic policies are changing. This includes its nuclear weapons program and nuclear deterrent policy, viewed as a critical guarantor of Beijing’s security and a tool that supports its growing regional and global interests. China’s evolving nuclear program and doctrine have multidimensional implications. This study critically examines the drivers of China’s ongoing nuclear weapons policy and force modernization by employing neoclassical realism. In doing so, it considers the implications of China’s nuclear program for international and regional security, and for strategic stability by exploring relevant case studies and dyads (China- US, China-Japan, China-South Korea, China-India, and China-Taiwan) and speculates on the future trajectory of China’s nuclear weapons modernization. In this context, China’s contemporary nuclear weapons force modernization is an ongoing process that started in late 2015 under President Xi Jinping’s rule. The hypothesis of this thesis extends from this line of thinking, holding that the emerging nuclear program of China is increasing regional and international strategic insecurity. This involves China, the US and other regional powers, manifested in a “security dilemma”.1 An empirical and analytical approach is used to evaluate the hypothesis and critically deconstruct prevailing discourses. The methodology employs deductive reasoning that uses existing theory as a foundation for formulating and testing the hypothesis. The findings show that China’s nuclear weapons policy and ongoing force modernization drivers are primarily structural. However, internal factors within China, such as its leadership and economic development, and bureaucratic competition between different services of the PLA also play a significant role in shaping China’s emerging full-spectrum deterrence posture calibrated towards limited nuclear war fighting. This breeds a spiral of insecurity vis-a-vis the US, Japan, South Korea, Taiwan, and India, is leading to greater strategic and crisis instability and an intensified security dilemma.