Below are some of the common questions that pop up when we talk to people outside of the field about nuclear weapons. The answers we provide below serve as an introduction to a complex issue with a 70+ year history.

We hope hope that you find our FAQs helpful. If you have any further questions, please email or tweet and we’ll do our very best to answer!



What is Trident?


What we call “Trident” is the UK nuclear weapons system. It consists of warheads that are made at Aldermaston and Burghfield, near Reading in Berkshire. They are attached to US Trident ballistic missiles and are carried in “Vanguard class” nuclear-powered submarines, based at the Faslane naval base near Helensburgh in Scotland. One of the four submarines is always at sea, on something called “continuous at sea deterrence”, which means that UK nuclear weapons are ready to be fired at a moment’s notice.


Is Trident dangerous when it isn’t being used?


The warheads are meant to detonate only if Trident is fired. However accidents do happen, and nuclear weapons have been dropped or caught up in fires. Under those kinds of circumstances, a warhead could be detonated or broken open, resulting in radioactive contamination of that area. See Eric Schlosser’s book Command & Control for real life examples of these scenarios. There are also worrying examples of miscalculation, miscommunication and near misses taking some countries to the brink of using nuclear weapons which have been detailed in this report by Chatham House.


What is the Trident warhead made of?

(Expand on this)The most dangerous part of the Trident warhead is the plutonium in the middle. The warhead is designed with various kinds of high explosives packed around the plutonium core. When the explosives are detonated they compress the plutonium instantaneously, causing a nuclear chain reaction. Within seconds the bomb explodes.

Isn’t the UK one of the countries that’s allowed to have nuclear weapons?


Under existing treaty obligations, the UK is not “allowed” to have nuclear weapons, but unfortunately some politicians act as if the UK is allowed to have and replace Trident.

In 1968, the UK was recognised as being one of the first 5 states – together with the United States, Soviet Union (now Russia), France and China – that had tested nuclear weapons when the Non-proliferation Treaty (NPT) was concluded and signed in 1968. The NPT, negotiated after the Cuban Missile Crisis took the world to the brink of nuclear war in 1962, was meant to sign all other nations up to obligations not to develop or acquire nuclear weapons. Nuclear disarmament by the five nuclear-armed states was part of the non-proliferation “bargain” to attract all the other states to join the NPT and agree not to get nuclear weapons.

When the UK signed the NPT it understood that this recognition of its nuclear possession carried a legal obligation on them to end the arms race and pursue nuclear disarmament in good faith, as well as working towards a treaty on general and complete disarmament. This nuclear disarmament obligation is often referred to as “Article VI” of the NPT, and is legally binding on the UK.

Over time, however, some UK politicians treated the NPT as if it conferred status without obligations. They acted as if the NPT allowed those first 5 nuclear-armed states to keep and even replace their nuclear weapons. They were wrong, as made clear in 2000, when over 180 nations negotiated a later agreement with them under under the NPT. Among other things, the consensus agreement of 2000, known as the “Thirteen Steps” specified the steps required to comply with Article VI. These included unilateral, plurilateral and multilateral reductions in existing arsenals and an “unequivocal undertaking to accomplish the total elimination of [current] arsenals”.


We haven’t had a nuclear war yet. Doesn’t that show that deterrence is working?


We haven’t had a full blown war using nuclear weapons, but there have been many near misses. The theory of deterrence is to have the weapons but not use them. According to many UK politicians, the very possession of nuclear bombs is meant to act as such a massive threat that they deter an adversary from attacking. They even call Trident “the deterrent”, as if the weapon and deterrence are the same thing. They aren’t.

Deterrence predates nuclear weapons. In fact deterrence has been part of defence for time immemorial. For deterrence to be successful, communication between adversaries is vitally important – understanding the other’s intentions and signals and predicting and calculating their fears and responses correctly are essential for deterrence. The history of deterrence with all kinds of different weapons is littered with different kinds of mistakes and failures.


Why does the Acronym Institute consider deterrence a red herring?


Many politicians call Trident “the deterrent”, but that’s misleading. Deterrence is not an attribute or type of weapon. It’s a complicated relationship between enemies or adversaries, and it can often go wrong. Politicians want people to associate nuclear weapons with deterrence so that the public will support having them but not think about firing them and destroying cities full of people.

The Acronym Institute’s 2013 submission on Deterrence to the House of Commons Defence Select Committee sets out some of our key security concerns about relying on nuclear weapons for deterrence.

Former US Secretary of State Henry Kissinger and other senior US nuclear practitioners such as Ronald Reagan’s Secretary of Defence George Shulz, Bill Clinton’s Defense Secretary William Perry, and the architect of US-Russia Cooperative Threat Reduction, Sam Nunn, wrote in 1007 that: “Reliance on nuclear weapons for [deterrence] is becoming increasingly hazardous and decreasingly effective.”

One problem with using nuclear weapons for deterrence is that they don’t deter terrorists or leaders who don’t think the UK will use them. They never deterred the wars the UK has fought with adversaries such as the IRA, Argentina (in the Falklands War), Saddam Hussein in Iraq, Al Qaeda or the Taliban in Afghanistan, or ISIS/Daesh. Despite having massive nuclear arsenals, Russia lost its war in Afghanistan, and the US lost the Vietnam War. India and Pakistan have fought border wars and suffered terrorist attacks despite both countries testing nuclear weapons 1998 and racing each other to make and deploy them ever since.

A second problem with nuclear deterrence is that if it fails, the consequences would be catastrophic and irreversible. The 1962 Cuban Missile Crisis was not the first example of a belief in nuclear deterrence taking the world to the brink of nuclear war. And it won’t be the last, unless we eliminate nuclear weapons. Chatham House, the British establishment’s think tank, recently wrote about 13 close calls after 1962, any one of which could have triggered nuclear war. There were miscalculations, miscommunications, misreading of computers and accidents that could have led to nuclear war. The lesson from their study is that as long as nuclear weapons exist – and especially if they are held on high alert, as Trident is – then mistakes can cause suspicious countries to launch nuclear weapons and risk nuclear war.

Like throwing yourself out of a 50 storey building, deterrence can feel like flying successfully – until you hit the ground. Hitting the ground whilst laden with nuclear weapons is not something we should be risking.


How can Britain get rid of it’s nuclear weapons? Ukraine did and it made them vulnerable.


Ukraine did not make itself vulnerable by getting rid of nuclear weapons. That’s a misconception. The conflict between Russia and Ukraine over Crimea has roots in history and the Cold War. Rebecca Johnson’s article in the Bulletin of the Atomic Scientists in March 2014, titled “Ukraine and Nayarit: the humanitarian case for nuclear disarmament” points out that nuclear weapons were irrelevant, neither causing nor preventing the Ukraine-Russia conflict.

Solving the Ukrainian-Russian conflicts over Crimea and other issues will not be easy, but to suggest they could have been prevented if Ukraine had held onto Soviet nuclear weapons is irresponsible. Nuclear weapons would only have made everything much more complicated and dangerous. Because Ukraine does not have nuclear weapons, Russia is not going to use nuclear weapons against Ukrainians. Despite some silly sabre rattling, even Putin knows that he cannot win this conflict by issuing nuclear threats.

It’s important to recognise that Ukraine never actually possessed nuclear weapons of its own. As Ukraine was part of the Soviet Union, some Soviet nuclear weapons were deployed on Ukrainian soil during the Cold War, but they remained operationally controlled by Soviet leaders in Moscow. When the Soviet Union broke up in 1990-91, big diplomatic efforts were made on all sides – especially by the United Nations, US and UK governments to persuade Ukraine, Belarus and Kazakhstan to hand the Soviet nuclear weapons to Russia and join the Non-Proliferation Treaty (NPT) as non-nuclear-weapon states. These negotiations resulted in the 1994 Budapest Memorandum, signed by Ukraine, Russia, the United States and UK. Britain contributed to the three newly independent nations of Ukraine, Belarus and Kazakhstan becoming non-nuclear and joining the NPT. This was considered a major step for international security.

If Ukraine had held on to the nuclear weapons on its soil, it could never have become an independent country. Nor could it have ever deployed or used the former Soviet nuclear weapons independently. No matter what has subsequently happened, Ukraine did the right thing in giving up the former Soviet nuclear weapons – not just for international security, but also for the security of the Ukrainian people. It’s both wrong and misleading for some British politicians to suggest now that Ukraine could have held onto those nuclear weapons and so avoided any future conflict with Russia.

If Britain got rid of Trident it would increase our security, but we should not delude ourselves that it would solve all this country’s political and security problems. See our responses [to other FAQs] for how the UK could get rid of nuclear weapons by combining multilateral negotiations to prohibit nuclear weapons with taking steps to end Trident replacement and take the existing Trident system off alert, pending total elimination.


If Russia and North Korea still have their nuclear weapons, how is it safe for the UK to scrap ours?


As long as the UK deploys nuclear missiles like Trident that could destroy Moscow and many other Russian cities, Britain will also be high on the list of the Kremlin’s targets. North Korean weapons, such as they are, do not pose a threat to the UK. Sadly the North Korean regime are trying to develop a nuclear arsenal because they believe that threatening to hit South Korean capital Seoul with a nuclear bomb is the only way to deter the United States. North Korea accelerated its nuclear programme after the US invaded Iraq.

It is safer for Britain to get rid of nuclear weapons than to hang onto them. The more we treat Trident as indispensable for British security, the harder it is for us to prevent the spread of nuclear weapons. The best way to free ourselves – and other nations – of nuclear threats is not to hang onto Trident, but to work with the majority of countries – nuclear and non-nuclear – to ban and eliminate all nuclear weapons.



What happens when a nuclear weapon detonates?


As we’ve seen in nuclear test explosions and Hiroshima and Nagasaki, when the warhead detonates there is a massive blast with a white-hot flash of blinding light and heat. Warheads are known by the size of the blast they cause. Trident can have a variable-sized warhead, but the usual is 100 kilotonnes (kt), which means that when it is detonated, the blast is as big as an explosion using 100,000 tonnes of TNT (give example of what destruction 100,000 tonnes of TNT would cause in London). By comparison, the Hiroshima bomb was around 12-13 kt, so most Trident warheads are 8 times bigger that the bomb that destroyed Hiroshima.

And then there is the radiation. When the plutonium and uranium in nuclear warheads are detonated they make everything they touch radioactive. Everyone nearby who manages to survive the blast, heat and fire will be contaminated with radioactivity.

The mushroom cloud that photographs show rising from a nuclear bomb detonation is made up of the buildings, people and ground that are turned to dust and then lofted high into the air by the explosion. The mushroom cloud is radioactive. While some of the dust is lofted high into the atmosphere, where it circulates in a dark cloud that cuts out sunlight, some falls to the ground as radioactive fall-out, which may be deposited as oily “black rain” or spread quite far before settling. Either way the radioactivity can contaminate agricultural land and other towns in its path.

Some kinds of radioactivity, especially from plutonium, carry on poisoning people and other living things for thousands of years. It depends on how much they ingest or absorb (the ‘dose’ they receive) and other factors. A big dose of radioactivity can kill within days. A smaller dose will take longer. Common symptoms of radioactive contamination include hair falling out, skin burns and blisters, and then cancer of various kinds.

For more information see Acronym’s ‘Preventable Threats: The Humanitarian Impacts of Nuclear Weapons: UK Risks and Challenges‘.



How many nuclear weapons are there in the world and who has them?


According to the Stockholm International Peace Research Institute (SIPRI), as of 15 June 2015, there were 15,850 nuclear weapons in the hands of 9 states: US, Russia, China, France, UK, Israel, India, Pakistan and North Korea. The first five were defined in the 1968 Non-Proliferation Treaty (NPT) as the ‘nuclear weapon states’ because they’d tested nuclear weapons prior to January 1967. During the Cold War (1945-91), the US and Soviet Union engaged in hugely expensive and risky nuclear arms race, amassing over 50,000 weapons by 1987. Most have been dismantled since then, but even today US and Russian arsenals account for over 14,500 nuclear weapons in the world.

Of the global nuclear stockpiles, 4,300 are deployed with operational forces. Around 1800 of these are dangerously deployed in a state of high alert, ready to be fired immediately an order or computer code is received. These are the most destabilising, and could be vulnerable to cyber crime.

During the Cold War, a handful of other governments came to rely on nuclear weapons as part of military alliances like NATO (the North Atlantic Treaty Organisation, covering much of Europe, Canada and the US), or the US-Japan, US-South Korea, and US-Australia agreements. Though majorities of people in these countries want to abolish nuclear weapons, the governments and some militaries are reluctant to denuclearise these alliances because they don’t want to offend the US. About 200 US bombs are deployed in five European countries under NATO: Belgium, Germany, Netherlands, Italy and Turkey. These are some of the most vulnerable because they are relatively portable, meant to be dropped from aircraft.

The rest of the world is nuclear free. Many of these countries began nuclear weapons programmes in the 1950s and ’60s, but decided after the Cuban Missile Crisis that they would be more secure nationally and regionally if they didn’t get nuclear weapons and instead pursued nuclear disarmament.   Among those who gave up nuclear programmes without even wanting any nuclear umbrella from the US were Brazil, Sweden, Switzerland and Argentina. South Africa, like Israel, made and deployed nuclear weapons for a while. South Africa decided in the early 1990s that their country would be safer without nuclear weapons, and went on to lead negotiations to make the whole of Africa into a nuclear weapon free zone (the Treaty of Pelindaba). These countries have all now signed treaty commitments not to make, use, deploy or possess nuclear weapons, through the NPT and often through regional nuclear weapon free zone treaties as well.

Israel, sadly, chose to build a nuclear arsenal (though the Israeli government refuses to confirm or deny this openly). Israel therefore drags its feet when other nations in the region want negotiations to make the Middle East a Zone free of all WMD. Yet a WMD-free zone in the Middle East would make Israel much safer than having an arsenal of nuclear weapons that it couldn’t possibly use without causing contamination and humanitarian suffering to the Israeli people as well and others.


Is eliminating nuclear weapons a realistic goal?


Yes, eliminating nuclear weapons is a realistic goal.   It is also a very achievable goal. Sooner than most people think.

Lots of weapons have been invented in the past and no longer exist except in museums. In some cases militaries decide that certain weapons don’t do the job they are supposed to, or are counterproductive. If the military and politicians decide that a weapon is not worth it, it stops being made and deployed. From there, the steps to eliminating the weapons are practical and achievable.

We already know how to dismantle and eliminate nuclear weapons. Since the end of the Cold War, the US, Russia, France and Britain have between them eliminated nearly 40,000 nuclear bombs of many different kinds. Although some reductions resulted from US-Russian treaties, the UK reduced its nuclear arsenal unilaterally.

In physical terms, eliminating nuclear weapons forever is simpler than eliminating biological or chemical weapons, and yet we’ve successfully banned and accelerated the elimination of both of those weapons of mass destruction (WMD).


Is it possible to put the toothpaste back in the tube?


Toothpaste can’t be stuffed back in the tube, but nuclear weapons aren’t like that. To eliminate nuclear weapons we have to learn the lessons from banning other inhumane weapons. Negotiate a treaty than bans them for everyone. Block access to the materials and technologies that make and deliver the weapons. Reduce existing stockpiles towards zero. Verify as much of the nuclear disarmament process as countries will agree to.

Biological and chemical weapons can be made from everyday pharmaceuticals. Hardly anyone tries to make or use these obscene weapons because they are prohibited and stigmatised and their use would be a crime against humanity. Even for terrorists, any use would be politically counter-productive.

Nuclear weapons are much harder to make. They require plutonium or highly-enriched uranium (called “fissile materials”). These radioactive fissile materials are very technically challenging and expensive to get right. As far as accidents or terrorism are concerned, the biggest risks occur when the nuclear-armed states are manufacturing transporting and deploying their weapons, not to mention if they were ever detonated – by accident or intention.


What would have to change for nuclear disarmament to happen?


When enough nations decide that a weapon should be eliminated, the first major step is to ban that weapon. As we’ve seen in recent years with the banning of biological and chemical weapons, landmines and cluster munitions, treaties can be negotiated and brought into force by a majority of governments even if not all the weapons holders are on board.

From recent history, we’ve seen that banning weapons takes away their legitimacy and value, and makes it much more difficult for governments to deploy, use or spend money on them. That, more than anything else, makes disarmament possible.

As long as it’s undertaken safely and securely, disarmament also makes the weapons less accessible and desirable for terrorists.

As the Austrian President told the UN General Assembly, nuclear weapons need to be stigmatised, banned and eliminated.

It still takes time to completely eliminate the weapons, but if they are prohibited then they are much less likely to be used, and the stockpiles are more quickly reduced towards zero. Moreover, if they are used, then anyone who has supplied or used them is held personally liable, as a criminal – including politicians or generals that give the orders.

The only way terrorists would be able to get nuclear weapons is to buy or steal either the actual weapons or enough of the fissile materials to make a weapon.

The best way to reduce the risks and dangers and prevent nuclear weapons being used or stolen is to stop the weapons of a handful of nuclear-armed countries being deployed and transported. These activities are prohibited for most countries, but only under a partial Non-proliferation Treaty (NPT) dating back to 1968. But the NPT didn’t go far enough. And it didn’t explicitly prohibit the use, deployment, production or transporting of nuclear weapons for all. For various reasons, the 9 nuclear-armed states don’t think the NPT applies to their own activities.

A nuclear prohibition treaty would be the best game-changing step we could take. Then instead of being objects of political desire, they become seen as an expensive problem to be managed and kept safe from terrorists. So a growing number of governments are now pushing for a new treaty to supplement and strengthen the NPT and non-proliferation regime.


How can nuclear weapons be banned if not all the countries who have them are on board?


Most weapons are prohibited while at least some militaries and countries want to keep and use them. If they are in the minority and if the majority have decided that the weapon poses an unacceptable risk and danger to their security, the “international community” is entitled to negotiate a treaty that will constrain the weapons holders for the sake of everyone.

Our own laws come from the same principle – just because some people want to carry guns, take drugs or commit rape doesn’t mean that the rest aren’t entitled to be protected by laws that prohibit carrying guns, taking drugs and making rape illegal.

Any use of nuclear weapons would be catastrophic, not only for the people who are targeted, but for whoever fired them as well. As discussed in Acronym’s 2014 briefing for MPs [LINK], one weapon detonated by accident or intention would be horrendous. It could also cause others to launch nuclear weapons and so lead to nuclear war on a bigger scale, with catastrophic consequences for all life on Earth.

Even if just a fraction of Britain’s nuclear weapons were used, the effects would cause such terrible humanitarian and environmental impacts that we would also be affected, perhaps by radiation, and perhaps by starvation as agriculture and economic and transport links that we depend on for food and other necessities would collapse.

The consequences of any use of British or any other nuclear weapons would be global – badly affecting the security and people of many nuclear free nations, as well as threatening their health and environment.

That’s why more than 140 countries in the world have decided they are better off without anyone having nuclear weapons, even though some of their neighbouring countries disagree. They point out that the nine nuclear-armed states threaten world security, and that the consequences of any of them making a mistake mean that it is the right and responsibility of everyone to ensure that nuclear weapons are never used again. While a treaty to ban them doesn’t solve the problem over night, it’s an important step towards reducing their value, which is a fundamental step towards disarmament.

Chemical and biological weapons, like nuclear, were invented for use in a past war, but they have been banned and are well on their way to being eliminated. If the weapon users are as likely to be harmed by the weapon they are using, then it’s not a very useful weapon. For the same reason, nuclear weapons aren’t able to be used. The moment a country fires them, they’ve lost whatever it was that they thought they were fighting for. That’s why most responsible military officers dislike nuclear weapons and consider them an expensive “white elephant”, taking resources away from real defence needs.

The main obstacle to eliminating nuclear weapons is political. Too many politicians in the nine nuclear-armed countries like these high tech WMD because they think they bring status.

As we’ve learned from other disarmament processes, including with chemical, biological and other weapons, the key to eliminating nuclear weapons is to get the majority of governments to negotiate a new, universally-applicable nuclear ban treaty. When the weapons are prohibited, then nations will put greater resources and intelligence into eliminating them.


Why do we need to act on getting rid of nuclear weapons now? They’ve been around for 70 years without a major incident.


There have been several very serious nuclear weapons accidents since 1945 which have spread plutonium contamination in various countries. We’ve been lucky that none of those accidents resulted in nuclear weapons actually being detonated. But such luck doesn’t last forever, especially when there are over 15,000 nuclear weapons in the hands of 9 countries which transport them around roads, by air and by sea.

Having committed to getting rid of nuclear weapons when we signed the Non-Proliferation Treaty in 1968, isn’t it time we actually started taking international security seriously by implementing our nuclear agreements? At that time we were one of five nuclear-armed countries. Now there are nine. The longer we delay, the greater the risk of more countries getting nuclear weapons. And the greater the risk that nuclear weapons will be detonated – by accident or intention. Having committed to nuclear disarmament, and twenty years after the end of the Cold War, when over 180 counries have made a binding commitment not to get nuclear weapons as long as we pursue disarmament, why are we still prevaricating?   If not now, then when?



Why is urgent action on nuclear weapons needed when we face other issues like climate change and terrorism?


As long as nuclear weapons exist, they threaten the safety and security of the world. At the same time, they are extremely expensive for the nine countries that have them, including the UK. The estimated cost of replacing Britain’s Trident nuclear weapons system currently stands at £176 billion. That’s a ridiculous waste of resources that would be far better spent on our real security needs, whether you see those as climate chaos (like flooding) or terrorism, or addressing our human security challenges such as health care and good education for the future.

To tackle climate change and terrorism, the UK needs to work with other countries. Trident doesn’t help tackle those major problems and if anything gets in the way.

Most of the world’s nations are pushing for the prohibition and elimination of nuclear weapons now. They’ve taken the plunge and made binding agreements to be free of nuclear weapons, and they want the nuclear-armed states to pursue nuclear disarmament in good faith so that as many nations as possible can focus together on solving other global threats without constantly fearing nuclear threats or that a nuclear-armed leader will go crazy, miscalculate deterrence, or have a nuclear accident.

Successive UK governments have said we support multilateral disarmament. Instead of voting against UN resolutions calling for nuclear disarmament negotiations, as the UK did in 2015, the UK should be taking the lead to make the world a safer place by prohibiting and eliminating all nuclear weapons.


What does the UN say about nuclear weapons?


For many years, the UN General Assembly, as well as successive UN Secretary-Generals, especially Kofi Annan and Ban Ki-Moon, have underlined that nuclear disarmament is a fundamental requirement for world security.

At the December 2015 meeting of the UN General Assembly there were several resolutions calling for nuclear disarmament. One, which more than two-thirds of the governments in the UN (139) voted for, uses diplomatic language to call for negotiations “for the prohibition and elimination of nuclear weapons”. Another resolution that got 138 votes established talks in Geneva in 2016 to take “forward multilateral nuclear disarmament negotiations”.

Disappointingly, the United Kingdom, France and the United States voted against both of these and almost all the other disarmament and nonproliferation resolutions.

But the other nations are determined to hold nuclear disarmament talks in 2016, so the clock is now ticking towards multilateral nuclear disarmament, with the probably next step being a nuclear ban treaty.




Where does the name the Acronym Institute come from and what does it mean?


The less serious answer, taking into account the voting choices in the UN General Assembly, is:


Control ,






Actually, as our name suggests, we are committed to disarmament and diplomacy, and not just controlling and reducing deadly weaponry.

The Acronym Institute for Disarmament Diplomacy started in 1994 as a project to monitor nuclear treaty negotiations, such as the Comprehensive Test Ban Treaty (CTBT) in Geneva, and related review conferences of the Non-Proliferation Treaty. The project was dubbed “Acronym” because the project brought together several UK and international non-governmental organisations (NGOs), and because we set out to explain negotiations so that they could be readily understood. Acronym’s name was also a reminder of our mission to explain the complicated acronyms and abbreviations that are often used to make disarmament seem more difficult and confusing than it really is. The name also reflects our flagship publication from 1996-2009, which was called “Disarmament Diplomacy”. After being continuously published for 13 years, our shift towards online publishing combined with reductions in our funding resources caused us to stop producing Disarmament Diplomacy.



About us

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