US Nuclear Policy in the XXIst Century

The dissertation is devoted to identifying the features of the United States' nuclear policy in the 21st century, considering the emergence of new challenges and threats, as well as changes in the strategic environment amidst the return of geopolitical confrontation, strategic competition among nuclear states, and the rapid spread of missile technologies. The research identifies factors that have determined the evolution of U.S. nuclear policy; highlights the main stages, priorities, and directions of policy implementation by various U.S. presidential administrations in the 21st century; identifies common and different traits in the approaches of presidential administrations regarding arms control, strategic defence, and nuclear non-proliferation; and analyses the role of Russian and Chinese factors in shaping and implementing U.S. nuclear policy in the 21st century. The dissertation substantiates the thesis that U.S. nuclear policy in the 21st century, encompassing issues of arms control, deterrence, and non- proliferation, is formed considering both the traditional approach, whereby official Washington remains a security guarantor for allies and partners in various regions, as well as current threats to international security. The features of the development of the international relations system in the new millennium have once again brought to the forefront issues regarding the strengthening of the role of nuclear weapons in state policies, leading to a crisis and decline in traditional mechanisms for maintaining effective nuclear deterrence, arms control, and countering the proliferation of weapons of mass destruction (WMD). Collectively, this changes the global nuclear order and necessitates the development and implementation of a nuclear policy that considers the dynamism and turbulence of the modern international security and strategic stability system, protecting the interests and security of the U.S., its allies, and partners in Europe and Asia, providing adequate and effective tools to counter current and anticipated challenges and threats to the non-proliferation regime and arms control at regional and global levels. The examination of U.S. nuclear policy features in the 21st century allows for conclusions that this policy is characterised by consistency and continuity from one president's administration to another on key issues, maintaining common traits that prove Washington's traditional policy on strategic matters. At the same time, it has been shown that in response to changing and unique trends in the strategic environment, U.S. presidential administrations have implemented specific elements of nuclear policy distinct from previous ones to achieve goals and address tasks considering the current state of the international relations and security system at global and regional levels. A characteristic feature of White House presidential administrations' approaches in strategic arms and defence, as well as nuclear non-proliferation, is maintaining the role of nuclear weapons and deterrence as fundamentals of U.S. policy and instruments for guaranteeing allies' and partners' security while simultaneously engaging in active diplomatic efforts to uphold strategic stability, arms control regimes, and nuclear non-proliferation. The study of Russia's and China's influence factors on U.S. nuclear policy in the 21st century showed that they are catalysts for destabilising the strategic environment and declining traditional regimes in the nuclear sphere. Their unconstructive stance on international cooperation to counter challenges and threats from missile-nuclear technology proliferation further exacerbates negative trends in strategic stability and disarmament. The scientific novelty of the obtained results is determined by the fact that the dissertation is an original, comprehensive, and thorough study of the nuclear policy of U.S. presidential administrations in the 21st century, taking into account current challenges and threats to strategic stability, arms control, and nuclear non- proliferation, which are only exacerbated by Russia's aggressive revisionist policy and the rapid modernization and increase of nuclear and missile arsenals of official and unofficial nuclear states.