Russian President Vladimir Putin issued a warning to the West in his TV address before the invasion of Ukraine, stating that anyone who interfered “will face consequences greater than any you have faced in history”.
The threat of nuclear war has been feared by world leaders and civilians since the days of the Cold War.
This is despite leading countries such as Russia, the United States and UK all having signed the Nuclear Non-Proliferation Treaty (NPT).
No country has used nuclear weapons since the Second World War, when US President Harry Truman dropped bombs on Japan, at Hiroshima and Nagasaki in 1945.
What is the NPT?
The Treaty on the Non-Proliferation of Nuclear Weapons is an international agreement signed by 191 countries intended to stop the spread of nuclear weapons.
There are three main parts to the agreement: non-proliferation, disarmament, and the right to peacefully use nuclear energy.
Only four countries with nuclear capabilities have not signed the NPT: Pakistan, India, Israel, and North Korea.
North Korea originally signed the NPT but became the only country to ever withdraw from it in 2003.
Which nations have nuclear weapons?
Nuclear weapons are known to be possessed by nine countries, but only five of these have signed the NPT.
According to the Arms Control Association Russia has the most, at 6,257, of which 1,458 are active (already deployed), 3,039 are available (can be deployed if needed) and 1,760 are retired (out of use and awaiting dismantlement).
The United States follows with 5,550 nuclear weapons in total, of which 1,389 are active, 2,361 are available, and 1,800 are retired.
Together Russia and the US have 90% of the world’s nuclear warheads.
Of the remaining NPT countries, the UK has 225, China has 350 active nuclear weapons and France has 290.
Pakistan has 165 nuclear weapons available, India 156, and Israel 90 - despite these countries never having signed the NPT.
North Korea is currently believed to have around 40 to 50 nuclear weapons.
Does Ukraine have nuclear weapons?
Ukraine is a nuclear weapon-free state, but has not signed the Treaty on the Prohibition of Nuclear Weapons.
It inherited nuclear weapons following the break-up of the Soviet Union, but these were all transported back to Russia after the signing of the Budapest Memorandum in 1994.
Ukraine signed the Memorandum, where in exchange for nuclear weapons the country sought iron-clad security guarantees.
The agreement was signed by Russia, Ukraine, Britain and the US, and promised that none of the nations would use force or threats against Ukraine and all would respect its sovereignty and existing borders.
As a result, between 1994 and 1996 Ukraine gave up its nuclear weapons.
In May 1996 Ukraine saw the last of its nuclear arms transported back to Russia.
Did Putin threaten to use nuclear weapons?
Putin addressed Russia on Thursday 24 February claiming his goal was to “demilitarise and de-Nazify” Ukraine.
He added: “To anyone who would consider interfering from outside: If you do, you will face consequences greater than any you have faced in history.”
France’s foreign minister Jean-Yves Le Drian said on French television channel TF1 that this message was understood to be a threat of using nuclear weapons.
The Russian President raised the stakes again on Sunday 27 February, announcing that Russia’s nuclear deterrence was being placed on “alert”.
While this threat is being taken seriously by the West, it has been called an act of “rhetoric” by UK
Are nukes likely to be used in the Russia-Ukraine war?
Nuclear options represent the most drastic and devastating weapon in the armoury of superpowers and the decision to use them carries the gravest consequences possible.
The possibility of nuclear weapons being used remains unlikely, as it would cause utter devastation to both sides - outweighing any conceivable strategic gains.
The Treaty on the Non-Proliferation of Nuclear Weapons, which has been in place since 1970, also provides an agreement between leading countries to peacefully use nuclear energy - not for mass destruction.
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