Nuclear weapons debate
After the bombings of Hiroshima and Nagasaki, the world’s nuclear weapons stockpiles grew, and nuclear weapons have been detonated on over two thousand occasions for testing and demonstration purposes. Countries known to have detonated nuclear weapons—and that acknowledge possessing such weapons—are (chronologically): the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, the People's Republic of China, India, Pakistan, and North Korea.
Treaty on the Prohibition of Nuclear Weapons
Among the countries voting for the treaty's adoption were South Africa and Kazakhstan, both of which formerly possessed nuclear weapons and gave them up voluntarily. Iran and Saudi Arabia also voted in favour of the agreement. There are indications that Saudi Arabia has financially contributed to Pakistan's atomic bomb projects and in return has the option to buy a small nuclear arsenal, an option that would be realized in the event that Iran obtains nuclear warheads.