Nuclear weapon
Since the atomic bombings of Hiroshima and Nagasaki, nuclear weapons have been detonated over 2,000 times for testing and demonstration.  Only a few nations possess such weapons or are suspected of seeking them.  The only countries known to have detonated nuclear weapons and to say they have them are (in order from the first time the country had tested them) the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, China, India, Pakistan, and North Korea.  Israel is believed to have nuclear weapons, but in a policy of deliberate ambiguity, does not say so.  Germany, Italy, Turkey, Belgium and the Netherlands share nuclear weapons with other countries.  South Africa is the only country that has independently developed and later renounced and dismantled its nuclear weapons.