1. Militarily: North Korea's missiles and nuclear weapons can threaten the United States and Japan or threaten China; It is geographical space that plays a decisive role in cracking down on Japan and Beijing. As long as North Korea has nuclear weapons, it is a threat to Beijing and China, and it is a substantial threat that China must guard against. 2. Economically, when China entered the bottleneck stage, it was forced to pay a huge price for North Korea's defense.

3. Diplomacy: North Korea can use nuclear weapons against China in the face of national survival or external attacks, including US nuclear strikes, so as to force China to carry out nuclear counterattacks against the United States and other countries, so as to curb the attacks of the United States and other countries on North Korea, thus achieving nuclear restraint and putting China in an extremely passive position.

4. From the follow-up: North Korea already possesses nuclear weapons, so Japan and South Korea also have reasons to possess nuclear weapons, which may trigger a nuclear race in East Asia, thus greatly increasing the unstable factors around China.