Top 10 Nuclear Power Countries

There are eight sovereign states that have successfully detonated nuclear weapons. Five are considered to be "nuclear-weapon states" (NWS) under the terms of the Nuclear Non-Proliferation Treaty (NPT). In order of acquisition of nuclear weapons these are: the United States, the Russian Federation (successor state to theSoviet 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. North Korea had been a party to the NPT but withdrew in 2003. Israel is also widely believed to have nuclear weapons, though it maintains a policy of deliberate ambiguity regarding this, and is not known definitively to have conducted a nuclear test.^[1]

South Africa has the unique status of a nation that developed nuclear weapons but then disassembled its arsenal before joining the NPT.

Nations that are known or believed to possess nuclear weapons are sometimes referred to informally as the nuclear club

Country	Warheads(Active/Total)[nb 1]	Date of first test	CTBTstatus	Delivery methods (According to the IISS)	Delivery methods (According to various sources)
The five nuclear-weapon states under the NPT
United States	2,104 / 7,315[3]	16 July 1945 ("Trinity")	Signatory[5]	Nuclear triad[6]	N/A
Russia	1,600 / 8,000[3]	29 August 1949 ("RDS-1")	Ratifier[5]	Nuclear triad[7]	N/A
United Kingdom	160 / 225[3]	3 October 1952 ("Hurricane")	Ratifier[5]	Strategic submarine-launched[8][nb 2]	N/A
France	290 / 300[3]	13 February 1960 ("Gerboise Bleue")	Ratifier[5]	Strategic submarine and air-launched[9][nb 3]	N/A
China	n.a. / 250[3]	16 October 1964 ("596")	Signatory[5]	Land-based and strategic submarine-launched[10]	Nuclear triad[11]
Non-NPT nuclear powers
India	n.a. / 90–110[3]	18 May 1974 ("Smiling Buddha")	Non-signatory[5]	Land-based[12]	Land-based and air-launched[13]
Pakistan	n.a. / 100–120[3]	28 May 1998 ("Chagai-I")	Non-signatory[5]	Land-based[14]	Land-based and air-launched[15]
North Korea	n.a. / <10[3]	9 October 2006[16]	Non-signatory[5]	N/A	Suspected to be land-based[17]
Undeclared nuclear powers
Israel	n.a. / Suspected 80[3][nb 4]	Unknown (suspected 22 September 1979)	Signatory[5]	Land-based and air-launched[20]	Suspected nuclear triad[21]