North Korea's nuclear issue and its stakeholders' policy choices: the origin and development of North Korea's nuclear issue 7-20 (1) the origin and development of North Korea's nuclear policy 7- 10 (2) the first nuclear crisis and its resolution1kloc-0/3 (3) the outbreak of the second nuclear crisis/kloc. Stakeholders' positions and policy choices on the North Korea issue in the third nuclear crisis 20-39 (1) The United States' tough stop policy 22 Japan's high-pressure sanctions policy 30-34 (5) Russia's denuclearization and multilateral coordination policy 34-39 III. The development prospect and crisis handling mechanism of the North Korean nuclear issue 39-54 (1) The essence of the nuclear crisis on the Korean Peninsula 39-42 (2) The crux of the North Korean nuclear issue-mutual hostility and extreme distrust 42-45 (III) The development prospect of the North Korean nuclear issue and the rational choice to solve it 45-48 (IV) The North Korean nuclear issue and the six-party talks mechanism 44