Nuclear Non-Proliferation Treaty
The treaty says that only five countries are allowed to have nuclear weapons. These are called nuclear weapons states. The five nuclear weapons states are China, France, the United Kingdom, the United States, and Russia. All five of these nations have all signed the treaty. They are not supposed to help any other nation build nuclear weapons. All other nations who sign the Nuclear Non-Proliferation Treaty promise not to build more nuclear weapons for themselves or others.