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.
List of states with nuclear weapons
The Soviet Union tested its first nuclear weapon ("RDS-1") in 1949. This crash project was developed partially with information obtained via espionage during and after World War II. The Soviet Union was the second nation to have developed and tested a nuclear weapon. The direct motivation for Soviet weapons development was to achieve a balance of power during the Cold War. It tested its first megaton-range hydrogen bomb ("RDS-37") in 1955. The Soviet Union also tested the most powerful explosive ever detonated by humans, ("Tsar Bomba"), with a theoretical yield of 100 megatons, intentionally reduced to 50 when detonated. After its dissolution in 1991, the Soviet weapons entered officially into the possession of the Russian Federation. The Soviet nuclear arsenal contained some 45,000 warheads at its peak (in 1986); the Soviet Union built about 55,000 nuclear warheads since 1949.