The US UK Australia nuclear submarine cooperation incident highlights the threat posed by nuclear proliferation to international security, and the issue of nuclear proliferation continues to receive attention from the international community. The Treaty on the Non Proliferation of Nuclear Weapons continued to play an important role after the Cold War. The study of nuclear proliferation involves both horizontal and vertical diffusion. The former refers to the spread of nuclear weapons from nuclear armed countries to non nuclear armed countries, while the latter refers to the advancement of nuclear technology among nuclear armed countries. This article summarizes the theoretical paradigm of nuclear diffusion research, explores the causes, logic, impacts, and response strategies of nuclear diffusion, and analyzes the problems existing in the research.

1、 The paradigm of the causes of nuclear proliferation

The paradigm of nuclear proliferation drivers involves four aspects: security requirements, domestic politics, technological dynamics, and international norms. As a national security tool, realist scholars believe that nuclear weapons are a product of self-help behavior norms. For example, the development of atomic bombs by Britain and the United States was due to concerns about Germany, and the development of nuclear weapons by the Soviet Union and China was also based on security considerations. In domestic politics, the attitudes of decision-makers and scientists have a significant impact on nuclear choices, and scientists may be both promoters of nuclear weapon development and supporters of nuclear arms control. Technological power is the driving force behind nuclear selection, and technology determinists believe that mastering nuclear technology is a prerequisite for developing nuclear weapons, but not a decisive factor. International norms consider nuclear weapons as a symbol of national identity and status, such as France and China developing nuclear weapons to showcase their national status. The proliferation of nuclear weapons is a reflection of national security, identity, international status, and nuclear science and technology. National nuclear choices are the result of multiple factors working together.

2、 The market and strategic logic paradigm of both parties in nuclear proliferation cooperation

The market and strategic logic paradigms of both parties in nuclear proliferation cooperation reveal the complexity of nuclear proliferation. In the early stages of the Cold War, the development of Soviet nuclear technology broke the United States' nuclear monopoly, prompting both the United States and Britain to realize the Soviet Union's ability to benefit from providing nuclear technology. Eisenhower's "Peaceful Use of Atomic Energy" speech marked a shift in nuclear technology diffusion, accelerated the process of nuclear technology cooperation, and formed a nuclear market dominated by the peaceful use of nuclear energy. The market logic describes the interactive relationship between the supply and demand sides of nuclear proliferation, with over 2000 bilateral civil nuclear energy cooperation agreements reached globally. The supply side gains economic benefits through the nuclear market, while the demand side obtains advanced nuclear technology. The supply side plays a dominant role in nuclear proliferation, and competition and cooperation affect market trends. The United States once had an advantage in the international nuclear trade market, but the rise of Western European countries in the 1970s weakened this position. The cooperation between suppliers is reflected in the establishment of the Sango Committee and the Nuclear Suppliers Group, aimed at coordinating export controls. The demand side enhances its nuclear weapon development capabilities through nuclear cooperation and becomes a potential nuclear weapon state. Strategic logic research has made up for the shortcomings of market logic. Nuclear cooperation is a choice for national military and economic strategies, such as the US UK Canada nuclear cooperation and the Eisenhower administration's "Atomic Marshall Plan". The international nuclear non-proliferation regime provides a basis for nuclear cooperation, but the supplier group has established stricter export control regulations. Both market logic and strategic logic are pathways for nuclear proliferation, and the risk of nuclear proliferation caused by nuclear cooperation is obvious. There is a causal relationship between peaceful nuclear cooperation and nuclear proliferation.

3、 The debate paradigm of right and wrong in nuclear proliferation

Nuclear proliferation has been a common concern among the scientific, political, and academic communities since the birth of nuclear weapons. The US government has refused nuclear sharing and closed the door to nuclear sharing with allies, but nuclear weapons inevitably spread from one country to multiple countries, even third world countries. There is a debate in academia between optimists and pessimists about the impact of nuclear proliferation. Optimists like Kenneth Waltz believe that nuclear proliferation can increase interdependence between countries and reduce the cost of war, while pessimists like Scott Sagan worry that biases and conventions in military organizations may lead to deterrence failure and trigger war. In addition, there is a debate on peace and conflict, where the nuclear weapons peace theory holds that the existence of nuclear weapons promotes peace, while the stability instability paradox holds that although the existence of nuclear weapons reduces strategic conflicts, it may increase conventional military conflicts. The debate on identity differences focuses on the acceptance of nuclear weapons by different countries, pointing out the Western fear and racist views towards third world countries possessing nuclear weapons, as well as the impact of democratic peace theory on the perception of identity differences in nuclear proliferation. The study of the paradigm of nuclear proliferation debate reveals the richness and complexity of nuclear proliferation issues, but there are also controversial issues such as excessive reliance on conceptual predictions, increased risk of nuclear war, and selective nuclear proliferation and double standards caused by identity differences.

4、 The paradigm for responding to nuclear proliferation

The issue of nuclear proliferation has attracted global attention, and countries, regions, and the international community have jointly taken various measures to address it. The idea of international control of atomic energy originated before nuclear weapons. US government officials recognized the international issues of nuclear weapons and promoted the establishment of the United Nations Atomic Energy Commission, but the proposals put forward by the US and the Soviet Union did not reach a consensus. The establishment of the US Atomic Energy Act and the Atomic Energy Commission reflects the US nuclear monopoly policy, but failed to prevent nuclear proliferation. Striking nuclear facilities is a means of preventing the development of nuclear weapons, as seen in the actions of the Allies against Germany and Japan, as well as Israel's attacks on Iraq and Syria, but this approach has complex implications. Sanctions are the "big stick" policy to deal with nuclear proliferation, and economic sanctions are the main means, but there are legitimacy issues with the United States' anti proliferation policy. Extended deterrence is a way for nuclear powers to provide nuclear protection, and the United States consolidates its relationship with its allies by providing a nuclear umbrella, but there are credibility issues. The cooperation between the United States and the Soviet Union in building an international nuclear non-proliferation mechanism, such as the Treaty on the Non Proliferation of Nuclear Weapons, is insufficient to deter countries determined to pursue nuclear weapons.

5、 Problems in Nuclear Diffusion Research

Research on nuclear diffusion has made progress in interdisciplinary, proactive, theoretical, and practical aspects, but there are still shortcomings. Firstly, there is insufficient research on the depoliticization of nuclear proliferation, and the dual military and political roles of nuclear weapons pose challenges to preventing nuclear proliferation. It is necessary to decouple nuclear weapons from national status. Secondly, the contradiction between the peaceful use of nuclear energy and nuclear proliferation is prominent, and the international non-proliferation system is difficult to effectively control the phenomenon of civilian nuclear energy projects accumulating dual-use nuclear technology. Thirdly, there is a dual understanding of nuclear weapons between national security and international security, making it difficult to reach consensus. The proliferation of nuclear weapons by non-state actors brings uncertainty to international security. Finally, the literature on nuclear proliferation research needs to be further enriched, as existing studies mainly rely on declassified archives from the United States and lack research results from multilateral or multinational sources.

6、 Summary

Nuclear proliferation is a core issue in international politics and security. Despite the existence of international nuclear non-proliferation mechanisms and consensus, issues such as illegal cooperation, double standards, modernization and politicization of nuclear weapons make it difficult to effectively control nuclear proliferation. Studying the theoretical paradigm of nuclear proliferation helps to understand its complexity, but faces challenges such as depoliticization, contradictions between nuclear energy utilization and proliferation, dual understanding of nuclear weapons, and limitations in data. The current anti nuclear proliferation policies and mechanisms are difficult to fully solve the problem, and nuclear proliferation will continue to exist. To overcome these problems, it is necessary to establish a favorable national development and international cooperation environment, and explore a nuclear proliferation governance model that adapts to the development of the times.