It is possible for a nuclear war to occur, as several countries possess nuclear weapons.
A nuclear war would have devastating consequences, potentially resulting in the loss of millions of lives and causing widespread destruction. The use of nuclear weapons would also have severe environmental and long-term health effects, and it could lead to a nuclear winter, which would affect global climate, agriculture and human survival.
The potential for a nuclear war has been a concern since the development of nuclear weapons, and efforts have been made to prevent such a catastrophic event from occurring. This includes diplomatic efforts to reduce the number of nuclear weapons, arms control agreements, and efforts to prevent the spread of nuclear weapons to other countries. However, the risk of a nuclear war still exists, and ongoing efforts to prevent one must be continued.