Here's a look at what you need to know about nuclear nations.
Information about nuclear stockpiles varies from source to source. The information below is sourced to the Nuclear Threat Initiative.
Countries with confirmed nuclear weapons:
China - 50-75 nuclear capable intercontinental ballistic missiles (ICBMs)
France - Approximately 290 warheads
India - 90-110 nuclear warheads
Pakistan - 90-110 nuclear warheads
Russia - 1,400 deployed ICBMs, submarine-launched ballistic missiles (SLBM) and heavy bombers designated warheads
United Kingdom - Approximately 180 nuclear warheads
United States - 1,654 deployed warheads
Countries with unconfirmed nuclear weapons:
Israel - Suspected to have enough plutonium for 100-200 nuclear weapons
Counties suspected of developing nuclear weapons:
Iran - In 2003, the IAEA releases a report about Iran's secret nuclear development over a period of 18 years. The report confirms that Iran has produced small amounts of enriched uranium and plutonium. Iran claims that it is developing nuclear power for peaceful reasons, its right under the 1968 Nuclear Non-Proliferation Treaty.
Countries that have the ability to build nuclear weapons, but claim not to have any nuclear ambitions:
Japan - On November 30, 2006, Japanese Foreign Minister Taro Aso states that Japan possesses the knowledge and ability to produce nuclear weapons, but has no plans to do so.
Countries that have abandoned nuclear weapons or weapons programs in recent years:
Belarus - Still has civilian nuclear program.
Kazakhstan - Although it inherited nuclear warheads after the collapse of the Soviet Union, Kazakhstan gave them back to Russia.
Ukraine - After the collapse of the Soviet Union, Ukraine had the third largest arsenal of nuclear weapons. Returned them to Russia.
South Africa - Renounced weapons program in 1991.