There is, of course, no such thing as ‘the nuclear button’, but the phrase is often used when world leaders, politicians and military commanders admit their readiness, or reluctance, to unleash atomic warfare. The devastating power of nuclear weapons, first demonstrated at the end of the Second World War in 1945 remains a controversial subject today, and has forced governments to reconsider their approach to conflict since.

During the Cold War, the global super powers of the United States and the Soviet Union dealt with the prospect of devastating nuclear consequences by adopting a strategy of mutually assured destruction, by which attacking the enemy would lead to the total destruction of the attacker themselves. Suggesting or your enemy perceiving that you might be willing to ‘press the nuclear button’ had considerable global consequences. In this high stakes game of global politics this made the choices far more complicated than just whether or not to push the button.

Pushing the button: Hiroshima and Nagasaki

Imploded glass bottle from Hiroshima, damaged during the Atomic bomb explosion 6 August 1945
© IWM (EPH 4631)
Imploded glass bottle from Hiroshima, damaged during the Atomic bomb explosion 6 August 1945.

On 16 July 1945, US President Harry Truman wrote in his diary ‘we have discovered the most terrible bomb in the history of the world’, after watching the first atomic bomb detonation in Los Alamos, New Mexico. Despite witnessing the incredible power of nuclear technology first-hand, in August 1945 the USA dropped atomic bombs on Hiroshima and Nagasaki on Truman’s orders.

The weapons killed thousands of people and the effects of radiation were long-lasting. But they did help to force a Japanese surrender, and meant that the Allies did not need to invade Japan, which saved other lives.

Being ready to retaliate: Nikolai Zaitsev

Black and white headshot of Nikolai Zaitsev, c 1945
Courtesy of Nikolai Stepanovich Zaitsev
Nikolai Zaitsev, c 1945.

After Hiroshima and Nagasaki, US leaders hoped that the threat of powerful nuclear attack would deter other nations from attacking the United States and its allies. The Soviet Union felt it had to defend itself against this threat and began to develop and stockpile its own nuclear capabilities. 

Nikolai Zaitsev served with the Russian Army. From 1957-1960 he advised senior officers on the capabilities of nuclear weapons, training them on how they could use them in operations. But while his job was to consider the very real ways the Soviet Union could use nuclear weapons against the United States, Zaitsev struggled to conceive that they could be used in aggression:

‘I never felt that these weapons would be used in real life… Only a person, who has no sense of the scale of damage that these weapons can cause to our planet could take a decision to use them. ‘

Readiness to push: David Sussman

You know, I can look back now and say it was sort of like a game. Very high stakes, very, very expensive video game. We knew they were there. We used to get briefings all the time. If the Soviets are going to attack, they are going to attack now. Because the number of missiles that they have plus the number of missiles that we have, it would be to their advantage if they attacked this week. Well, this week would come and go. So we were very, very aware, and we knew what we were doing. But you know, it’s like we didn’t have an emotional dog in the fight. It was a job. And we did it. After I retired… maybe within a year… yes, all of those things, I thought about them. But while I was in the Air Force – no. I don’t know if it was me, or if it was all of the SAC crew members. I mean we were cold, professionals. That’s what they drummed into us so long. And we trained so much that it was all second nature. If we had gone to war with the Russians, we would have flown over there, I would have unlocked my handle and we would have dropped our bombs and never given it a second thought. 20 years later, I can think about this stuff. Yes, it wells up a lot of emotion.

From 1957 the US Air Force deployed B-52 Stratofortress bombers armed with nuclear weapons on round-the-clock flights close to the borders of the Soviet Union. The programme enabled the US to adopt a state of permanent readiness for nuclear warfare. David Sussman served on B-52s nuclear alert missions from 1960- 1968, but it was not till after he retired from the US Air Force that he fully considered the consequences of his work.


‘If we had gone to war with the Russians, we would have flown over there, I would have unlocked my handle and we would have dropped our bombs and never given it a second thought. 20 years later, I can think about this stuff…it wells up a lot of emotion.’

David Sussman’s yellow ‘war hat’ worn while he was stationed in South East Asia in 1968. The yellow had has embroidered red flowers and blackbirds and reads "Make love not war".
© IWM (AE264.1)
David Sussman’s ‘war hat’ worn while he was stationed in South East Asia in 1968.

Sussman was an Electronic Warfare Officer, and on missions answered messages from headquarters, which could have ultimately ordered his crew to drop their nuclear weapons on the Soviet Union.

As Electronic Warfare Officers were also known as ‘Ravens’, when Sussman commissioned this “war hat” in South East Asia in 1968, he chose the inscription ‘Nevermore’ in reference to Edgar Allen Poe’s poem ‘The Raven’, where the titular bird utters a prophetic warning.

The highest moments of tension in the Cold War were often when the United States and Soviet Union misinterpreted the others actions. Misjudgement on either side about the intentions of the other had the potential to unleash global nuclear warfare.

During the Cuban Missile Crisis of 1962 the Soviet Union and the United States teetered on the brink of nuclear conflict, after US intelligence discovered Soviet missiles on Cuba. Over the course of thirteen days, tensions escalated to perilous levels until the threat of mutually assured destruction led both sides to agree to keep their fingers off the nuclear button.

Maintaining control: Sergei Khrushchev

My father was under strong pressure but much less pressure than during the Stalingrad battle. He went through so many crisis that he told… we understand, me and America's president we mustn’t lose control. We can negotiate, we can do everything, but we have to prevent first shot. At the first shot, it will be going in the different direction and the military will take over. It was not such shot like shooting the U-2 or some other possibility. But if you really start invasion, or you start this then you cannot stop this. It will go to the wall. So there was very cautious. And in three days of these negotiations, both sides came to the conclusion – too dangerous to keep on such level. 

You cannot have everything. But you have hopes on the both sides. And Americans wanted to take Soviet missiles out together with Castro and take over the island. Soviet hopes wanted to prevent American invasion, still keep the missiles there. Even if they were useless from the practical point of view. And it is embarrassment that we have to take them out. I was somewhere in between. From one side, of the hopes I want to the missiles to stay there. From the other side, I was witness of all these negotiations and I understood it was very important to prevent the real war. And it was not crazy, I didn’t want to die. So but it was this controversy, like everywhere.

Historian Sergei Khrushchev, the son of the Soviet Premier Nikita Khrushchev, watched his father deal with this volatile situation, and explains how Khrushchev and US President John F Kennedy ultimately came to negotiate.


‘He [My Father] went through so many crisis that he told me: we understand, me and American president – we mustn’t lose control. We can negotiate, we can do everything, but we have to prevent first shot.’

Taking your finger off the button: George H W Bush

Suit worn by President George H W Bush
© IWM (UNI 16161)
Suit worn by President George H W Bush.

As President of the United States, George H W Bush could order the use of nuclear weapons, but as a veteran of the Second World War he understood what the consequences of his decisions could be, particularly when committing forces to battle.

After working on treaties to limit the number of nuclear weapons on 27 September 1991 Bush ordered the nuclear armed B-52 fleet to stand down from its state of permanent readiness. The move was one of several Presidential nuclear initiatives undertaken which saw the United States act on its own nuclear posture, while at the same time challenging the Soviet Union to do the same.

The U-2 and the Cuban Missile Crisis

The U-2 entered service in 1956. The U-2 overflights across the Soviet Union were incredibly dangerous missions. Every flight was at risk of being perceived as an unauthorised invasion of another country’s airspace and at risk of leading to nuclear war. So why did the US government risk so much on these U-2 missions? Curator Carl Warner tells us more in this video. 

In the mid-1950s, the United States was desperate to know what was going on behind the Iron Curtain. No information had come out of the Soviet Union since the Second World War, and the US government was increasingly talking about a missile gap, and the idea that the Soviet Union were technologically superior. 

The gathering of photographic aerial intelligence was deemed essential.

Under the code name "Bald Eagle" the USAF began to solicit designs for an aircraft capable of the dangerous reconnaissance overflights of the Soviet Union.

Now, as air defences got better, as each side began developed aircraft that could intercept bombers, that could fly up and shoot down enemy aircraft, one of the crucial things was, if you're going to take good quality photographs, you need to do it at height.

But in order to do that, that aircraft had to have some very, very special properties. It needed to be out of the range of Soviet air defences, particularly aircraft, so it couldn't be shot down. It needed to be able to fly over long distances. It needed to carry the right sort of equipment to take those images. And crucially, it needed to be able to come back time after time.

They turned to engineer Clarence Kelly Johnson and his team known as the Skunkworks. Just 8 months after being given the contract, Skunkworks delivered the first U-2 - effectively a high-flying powered glider that operated on the edge of space.

The U-2 entered service in 1956. The aircraft had a flight ceiling of 70,000 ft, initially believed to be beyond the reach of Soviet fighters, missiles and radar.

Even so, every U-2 mission was dangerous, but they risk was deemed essential.

Herbert York: The U-2 flights started precisely because we were uncertain about what was going on and we wanted to know more about it, in particular President Eisenhower. So everyone knew that the U-2 was a deliberate violation of international norms and everyone knew that eventually the U-2 would come a cropper, that it would be shot down, but nevertheless the need for better information than we had was so great that we went ahead with it anyway.

Every flight was at risk of being perceived as an unauthorized invasion of another country’s airspace. It was agreed that the overflights would be operated by the CIA rather than the military, so that in the event of being shot down, the flight was less likely to be perceived as an act of war. To complicate matters, the U-2 was not exactly a particularly easy aircraft to fly.

All of the trade-offs that Kelly Johnson had to make to enable that aircraft to fly at such height and to take those images made it incredibly difficult for the pilots.

Even just taking off and landing, to preserve that narrow, pencil thin fuselage. It had a bicycle undercarriage. It required props under each under each wing.

It's designed to give off its best in the rarefied atmosphere of 70,000 ft close to space and in the thicker air closer to earth, that makes it a very difficult prospect for the pilot to fly, especially as he's on oxygen, he's fully suited up, almost like an astronaut, eating food out of a tube and drinking water out of a tube.

The pilots needs to be able to feel the movement of their aeroplane. They need to be able to have an instinctual relationship with that aircraft. So it was the very best pilots that were selected to fly the U-2.

My last flight was flying the U2. It’s a magnificent platform. It’s demanding on the pilot. The men and women that fly the U-2 – they’re going up for 10 sometimes 12 hours at a crack – you’re in that same pressure suit environment. Err you come back in, you have to stall the airplane. It’s got to come down on its rear wheel first – if the nose wheel touches it will go down a whole 10,000ft runway and never land. But it’s an aircraft of the past.

Despite the challenges involved, the U2 supplied the US with critical information that it could not have obtained elsewhere. In four years of overflights, the U-2s completed around 30 reconnaissance missions – approximately 90% of their hard intelligence data came from U-2 cameras. But the CIA were always aware of the risks.

Buz Carpenter: Going into this affair, we all believed that the U-2 would not be seen and the Russians wouldn't know we were there. That fallacy lasted until the first penetration of denied territory. It turned out, in retrospect, the U-2 was really quite invisible to American radar, but Russian radar were a little different - better, you might say. I can remember squadrons of fighters beneath the U2 trying to reach up and knock it down.

Then in 1960, Francis Gary Powers set off from Pakistan at 6am. He was expected to fly some 2,900 miles of Soviet airspace before arriving into Norway. But half way into his mission, he disappeared.

This is the partial pressure helmet and partial pressure suit that was worn by U-2 pilots, including Gary Powers. He's wearing something very much like this when on the 1st of May 1960 he was shot down by a Soviet SA2 surface to air missile.

It was, in fact a near miss. It just needed to explode close enough to the fragile and complex U-2 to cause it to spin wildly out of control and begin to disintegrate.

Powers was able, finally, as this aircraft came down, to get out, to parachute down and was, in fact, captured and taken prisoner by the Soviets.

The CIA, believing Powers to be dead, claimed that the aircraft had in fact been performing a weather flight. The Soviets meanwhile not only had Powers alive and captured, but had the aircraft wreckage itself along with the photographs it had been taking.

The East-West Paris Summit was due to take place a matter of days later. The US and USSR had been making significant progress towards a peace agreement. This event was not only embarrassing for Eisenhower and the US, it was a disastrous escalation of tensions.

Khrushchev wanted Eisenhower to both apologize for the past flights over his country and to say that they wouldn't do them again. Eisenhower didn't do this. Eisenhower was still not keen on admitting that the program existed. And so the Soviets actually pulled out of the peace conference that was to go ahead in Paris.

Gary Powers was placed on trial in the Soviet Union, a grand occasion that was widely publicized and televised. He was sentenced to ten years, including seven years of hard labour. But in fact he served just under two years after being exchanged for a Soviet spy.

But in the years that followed his capture, an unwarranted feeling of mistrust of Powers began to take hold in the United States.

He was a man who could dedicated his life to serving the United States. And yet there are always questions about, Well, why didn't he kill himself? Why didn't he use his poison device? And this kind of followed Powers, even despite the fact that he was completely exonerated. And it's interesting to think that this this one man who did something that is quite extraordinary had to face so many questions about both his bravery and his commitment to his country.

So Khrushchev abandoned the Paris Summit. And the possibility of an arms control or peace deal were closed down. Eisenhower left office and young John F Kennedy took over.

Just three months after Kennedy’s inauguration, one of the biggest incidents of his presidency took place.

The United States had been becoming deeply concerned about the situation in Cuba, after the nation had become communist under Fidel Castro in 1959.

There were many Cuban exiles living in Florida who desperately wanted a change of government, and the US government did not want to see Cuba maintained as a communist state.

And so President Eisenhower had agreed to a plan whereby Cuban refugees who had been trained and armed in the United States would launch an invasion and take back the island from Castro. Now, Eisenhower left office, but this plan remained on the books, and President Kennedy signed it off, but he signed it off in a limited way. He didn't want the US to be too involved.

The invading forces were badly outnumbered. The invasion was a failure.

The Bay of Pigs was a very clear message sent to Castro and indeed to the Soviet Union. They said the United States was prepared to back an overthrow of that regime. Castro reached out to the Soviet Union for protection.

And so that led to Khrushchev eventually agreeing to station nuclear missiles in Cuba.

On 14 October 1962, a U-2 brought back images that revealed what the US feared.

The photos essentially revealed that in several locations in Cuba, Soviet missiles were being brought in, unloaded and made ready to launch.

The camera used on the U2 was the Hycon Model 73B, known as the B camera. It was capable of identifying objects as small as 2 and a half foot from a height of 60,000ft. The photos clearly revealed that there were medium-range and intermediate-range ballistic nuclear missiles under construction in Cuba that had the capacity to reach San Francisco. This wasn’t a new threat militarily – Soviet missiles already had the capacity to reach across the US – but the political implications of having them on their doorstep was a huge issue.

So what were Kennedy’s options? If he did nothing, the world would think that the Soviet premier had pushed the president into a corner. All of Kennedy’s Joint Chiefs of Staff believed air strikes were the best option. But Kennedy was reluctant to take that step. A middle ground was chosen: a naval blockade of Cuba was actioned.

Alongside which, regular photographic reconnaissance was necessary to confirm or deny whether those missiles were ready for use.

The next 13 days were some of the most dangerous that the world has ever faced.

Then on 27 October, something happened that brought the crisis to the brink. The first shot was fired.

So in conventional warfare, actions have consequences. And they're well understood. If one of your aircraft is shot down, the normal next step is to retaliate.

But the problem in the situation in Cuba is that any escalation could lead eventually to nuclear conflict.

And this, of course, became a direct problem on the 27th of October 1962, when Major Rudolf Anderson piloting a U-2 on a reconnaissance flight over Cuba was shot down by a Soviet surface to air missile.

Anderson had taken off from a base in Florida and just a few hours into the mission, two surface-to-air missiles rocketed into the sky, one exploding near his U-2. Shrapnel pierced his flight suit and helmet, likely killing him instantly. Anderson was the first and only American casualty during the Cuban Missile Crisis.

Kennedy and his advisors began to prepare for an attack on Cuba within days, unless a diplomatic resolution could be found. 

The US government thought that the Soviets would then move on West Berlin, that the Americans would be forced to retaliate, and that very quickly, a nuclear war would occur.

On the other hand, this was also an opportunity to realize how far down the road of conflict both sides had gone.

Khrushchev did not want this to precipitate a nuclear war. Kennedy certainly didn't either. Back channels that were established between the United States and the Soviet Union in order to smooth over and try and work out the situation without it escalating out of everyone's control began to be used.

A deal was reached directly between Khrushchev and Kennedy. The missiles would be removed from Cuba if the US agreed to not invade. And another provision was tacked onto the end of the agreement: the US would also take its nuclear missiles out of Turkey.

This wasn’t publicly acknowledged by the United States. But a few months later, those missiles that were threatening the Soviet Union were withdrawn.

The U-2 played a pivotal role in two of the most famous events of the Cold War, the shooting down of Gary Powers and the Cuban Missile Crisis. And the U2 was at the centre of these events because gathering photographic intelligence was so important. It was a fact recognized during the Second World War. It was a fact recognized by Eisenhower. And it’s a fact that is still true today. And for that reason that the U-2 is still in service. Some people assume that because we now have satellites and drone technology, that things like the U-2 are not required.

But satellites, for example, are quite predictable. It's easy to know when a satellite will be overhead. An aircraft like the U-2 can provide the sort of intelligence that is needed whenever it's needed.

The U-2 has been upgraded many times with new systems, with new camera technology… But essentially, the missions are the same. And the aircraft is very much the same. The things that Clarence Kelly Johnson designed into that airframe to allow it to fly so high and for so long are still vital to the way executes its missions today.

And it's for that reason that aircraft like this are in service today. And the requirement for aircraft like this to carry out those jobs will likely continue for many years to come.

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