| Nuclear weapons are not only essential to maintaining the security of the United States and its allies,but also a key means to deter potential adversaries from attacking the U.S.and its allies or important interests,and successive U.S.administrations have developed corresponding nuclear strategies based on the external environmental threats they faced at the time.In recent years,some experts and scholars have proposed the concept of "the Third Nuclear Age" to provide theoretical support and ideas for the transformation of U.S.nuclear strategy in the context of great power competition.Therefore,this paper will take "the Third Nuclear Age" proposed by the U.S.as a perspective,elaborate the background and policy intention of the U.S.in proposing the concept of "the Third Nuclear Age",make an in-depth analysis of the U.S.nuclear strategy adjustment in this period,and make a prediction on its future direction,so as to provide some reference and reference for China’s nuclear response policy in the context of the competition between China and the U.S.This paper is divided into five chapters.The first chapter discusses the temporal scope and characteristics of "the First Nuclear Age" and "the Second Nuclear Age," and further explains the purpose of the U.S.concept of "the Third Nuclear Age.The second chapter discusses the scope and characteristics of "the First Nuclear Age" and "the Second Nuclear Age" respectively.Chapter 2 provides an in-depth analysis and discussion of the U.S.nuclear strategy in "the Third Nuclear Age" from four major aspects: nuclear deterrence,nuclear force development,nuclear force employment,and nuclear arms control.Chapter 3 discusses the reasons for the changes in U.S.nuclear strategy at the systemic,national,and policy maker levels.Chapter 4 analyzes the impact of the current U.S.nuclear strategy on individual countries,the regional situation,and global arms control from the perspective of the initiatives related to the adjustment of the U.S.nuclear strategy.Based on the current environment of the changing world landscape and the governing style of the new President Biden,Chapter 5 provides a cursory consideration of the overall development of the U.S.nuclear strategy in "the Second Nuclear Age" and proposes nuclear response strategies with Chinese characteristics that are consistent with China’s reality. |