In order of acquisition of nuclear weapons these are: the United States, Russia (the successor state to the Soviet Union), the United Kingdom, France, and China. Since the NPT entered into force in 1970, three states that were not parties to the Treaty have conducted nuclear tests, namely India, Pakistan, and North Korea.
States that formerly possessed nuclear weapons are South Africa (developed nuclear weapons but then disassembled its arsenal before joining the NPT) and the former Soviet republics Belarus, Kazakhstan, and Ukraine.
Pakistan also is not a party to the Nuclear Non-Proliferation Treaty. Pakistan covertly developed nuclear weapons over decades, beginning in the late 1970s. Pakistan first delved into nuclear power after the establishment of its first nuclear power plant near Karachi with equipment and materials supplied mainly by western nations in the early 1970s.
In order of acquisition of nuclear weapons these are: the United States, Russia (the successor state to the Soviet Union), the United Kingdom, France, and China. Since the NPT entered into force in 1970, three states that were not parties to the Treaty have conducted nuclear tests, namely India, Pakistan, and North Korea.
It tested the first nuclear weapon on July 16, 1945 ("Trinity") at 5:30 am, and remains the only country to have used nuclear weapons in war, devastating the Japanese cities of Hiroshima and Nagasaki.
States that formerly possessed nuclear weapons are South Africa (developed nuclear weapons but then disassembled its arsenal before joining the NPT) and the former Soviet republics Belarus, Kazakhstan, and Ukraine.
In February 2005, North Korea claimed to possess functional nuclear weapons, though their lack of a test at the time led many experts to doubt the claim. However, in October 2006, North Korea stated that, in response to growing intimidation by the United States, it would conduct a nuclear test to confirm its nuclear status.