Which countries have nuclear weapons?
Nine countries currently have nuclear weapons – some legally and some illegally – with an estimated 12,100 warheads between them as of early-2024
Tensions in the Middle East have reached boiling point in recent weeks as Iran fired an unprecedented barrage of missiles at Israel on 13 April, which responded with its own reported missile attack.
Neither country reported any injuries, with Israel confirming that the 300 missiles and drones launched by Iran had been shot down, and Iranian state media saying in turn that Israel had launched three drones that had been taken down by its air defences.
Iran has said it would not retaliate immediately over the attack as the "shadow war" that had long played out between the countries was pushed into the open, prompting fears of a larger-scale regional war.
But a senior commander for the Iranian Revolutionary Guards did warn on Thursday that Iran could review its "nuclear doctrine" if threats from Israel continue - despite Iran currently having no nuclear weapons.
As the situation in the Middle East becomes increasingly fraught, Yahoo News explains which countries have nuclear weapons.
Which countries have nuclear weapons?
Nine countries currently have nuclear weapons – some legally and some illegally – with an estimated 12,100 warheads between them as of early-2024, according to the Federation of American Scientists (FAS).
Five nations are officially recognised as possessing nuclear arms by the Nuclear Nonproliferation Treaty (NPT).
These are the UK, China, France, the United States and Russia.
But there are also four nations who hold the weapons illegally – India, Pakistan, Israel and North Korea.
Russia has the most nuclear weapons followed by the US.
Iran does not have nuclear weapons, however, its store of enriched uranium stood at 5.5 tonnes in February, according to the UN nuclear watchdog. Its uranium is currently enriched to 60% and it theoretically has enough material for two nuclear weapons if enrichment continues, Reuters reports.
Number of nuclear weapons per country
While the official number of nuclear weapons tends to be a state secret, the FAS estimates that Russia has 5,580, as of 2024.
This is closely followed by the US, which has an estimated 5,044.
In fact, the FAS says that approximately 88% of all nuclear warheads are owned by Russia and the US.
Meanwhile, no other nuclear-armed state sees a need for more than a few hundred nuclear weapons for national security.
That's why China, which comes in third, has just 500 in comparison to the thousands owned by Russia and the US.
France follows with an estimated 290 warheads, then the UK with an estimated 225.
How the number of nuclear weapons are distributed around the world
Out of the countries that hold nuclear weapons illegally, the FAS says Pakistan has around 170, India has around 170, Israel has around 90 and North Korea around 50.
But these totals also include weapons that are still intact but are queued for dismantlement.
Israel does not publicly acknowledge it has nuclear weapons.
As countries commit to nuclear disarmament, the number of weapons that remain in their military stockpiles is decreasing.
These stockpile numbers can also be broken down into different categories depending on whether the weapons are deployed on launchers at military bases or are being kept in reserve.
According to the FAS, the entire "military stockpile" includes all active and inactive warheads that are in the custody of the military and earmarked for use by commissioned delivery vehicles.
Meanwhile, "deployed strategic warheads" are those deployed on intercontinental missiles and at heavy bomber bases.
Currently, there are 9,583 nuclear warheads in military stockpiles (that can be used for missiles, aircraft, ships and submarines).
Of these, 3,880 are deployed, while there are 2,000 "high alert" warheads that belong to the US, Russia, Britain and France, which can be deployed at short notice.
"Deployed nonstrategic warheads" are those deployed on bases with operational short-range delivery systems.
Most warheads in the world are in reserve or "non-deployed", meaning they are in storage rather than deployed at military bases.
For Israel, Pakistan, India and North Korea, their entire military stockpiles are non-deployed, according to the FAS – meaning none are currently deployed.
Only two nuclear weapons have ever been used in warfare since they were first developed by the US during the Second World War.
The US dropped two bombs on the cities of Hiroshima and Nagasaki in 1945, killing almost 200,000 people in total.
Both Russia and the US continued to build up their stockpile of nuclear weapons during the Cold War as tensions escalated.
The latest nation to build nuclear weapons is North Korea, which carried out its first nuclear test in 2006.
The FAS estimates there have been over 2,000 nuclear tests conducted to date.
Since the Cold War, the global nuclear stockpile has massively diminished - down from around 70,300 in 1986 to around 12,100 in 2024.