Professor Serhii Plokhy could be forgiven for feeling downbeat. The Harvard historian is visiting family in his native Ukraine and things are looking grim.

“It’s more dangerous now in Kyiv than it was the last time I was here,” the 68-year-old says, speaking over video chat. “And it’s more dangerous the closer you get to the front line. But there is a determination in Ukraine, we are saying, ‘we are here, we are staying, we will fight’.”

While he is optimistic about Ukraine’s ability to hold its own, on the wider world stage Plokhy believes we are at a moment of immense danger, more hazardous even than at the height of the Cuban missile crisis.

“I think we are in a more dangerous world today than we were in October of 1962,” he says.

His new book, The Nuclear Age, traces the history of nuclear armaments from the early work on nuclear physics by Ernest Rutherford and Frederick Soddy to the Manhattan project, the Cold War and the steady build-up of new nuclear players after the collapse of the Soviet Union.

“We are in a worse situation today because there are more drivers on the nuclear highway — and they are driving without their lights on,” he says. During the Cuban missile crisis, when the US and USSR came perilously close to all-out nuclear war, the only other nations with nuclear capabilities were Britain and France.

Ukrainian historian Serhii Plokhy sitting in front of a bookshelf.

Serhii Plokhy

SIMON SIMARD

Since then China, Israel, India, Pakistan and North Korea have joined the club, and many others are looking to join. Most of them will not play by the same rules. “If the international system loses its current balance and the global and regional rivalries that have fuelled the nuclear proliferation of recent decades veer out of control, we may soon see as many as 40 additional nuclear-armed countries in the world, about five times as many as there are today,” Plokhy warns.

Will fear of mutually assured destruction save us in new nuclear order?

In the aftermath of the Cuban missile crisis, America and the Soviet leaders, terrified by how close they had come to annihilation, set up a series of checks and balances — treaties, hotlines and arms control agreements — to oversee nuclear development. Fear, in the 1960s and 1970s, was a force for peace. Mutually assured destruction meant nobody would use their weapons.

These days, Plokhy argues, fear has returned — but it is only likely to make conflict more likely. In his book he writes: “With the Cold War agreements gone and a new, unregulated arms race under way, fear is back, poised this time to fuel an arms race that at best will turn out to be a huge waste of money and resources, and at worst might lead to a nuclear confrontation.”

What does he mean by this? “When you meet a lion in the jungle, fear can mobilise you to run faster than you would run otherwise,” he says. “Or it can paralyse you or make you run in the wrong direction.”

He points to the example of the West’s relationship with Vladimir Putin, who has repeatedly hinted that Russia would use its nuclear arsenal if Nato members interfered in the Ukraine war. Outsiders would see consequences “such as you have never seen in your entire history”, Putin warned as he invaded in February 2022.

But fear of Putin’s actions have prolonged the war, Plokhy says, because western countries have held back from becoming involved more fully. “It is classic appeasement. You hope that if you feed the lion its appetite will be satisfied, but its appetite is actually built up.”

Part of the problem has been an imbalance of power which stems from Ukraine’s agreement to give up its nuclear arsenal in the Budapest memorandum of 1994. In return for giving up the weapons it had inherited from the Soviet Union — at that point the world’s third largest arsenal — the United States, United Kingdom and Russian Federation swore to protect Ukraine’s sovereignty.

Soldiers preparing to destroy an SS-19 ballistic missile at a former Soviet military rocket base in Ukraine.

Soldiers prepare to destroy a ballistic SS-19 missile e in Vakulenchuk, 137 miles west of Kyiv in 1997 and, below, a Ukrainian officer beside the final SS-19 missile booster to be destroyed

AP

Ukrainian officer walking next to an SS-19 nuclear missile booster.

“It was considered to be an absolute success story from the point of view of non-proliferation,” Plokhy says. “But it created a security vacuum, removing weapons of deterrence from the territory of Ukraine, and didn’t replace them with any other deterrence.” That meant Putin felt free to invade 28 years later. “The Budapest memorandum was responsible for the largest war in Europe since 1945.”

And the nature of warfare has changed. For the first time in history, a full-scale conventional war is being waged on and around civilian nuclear power facilities — at Chernobyl and Zaporizhzhia, the largest nuclear power plant in Europe, close to where he visited relatives last week. Attacking one of these plants could turn it into a dirty bomb, he says.

A Russian service member stands guard near the Zaporizhzhia Nuclear Power Plant.

A Russian guard at the Zaporizhzhia nuclear power plant, now protected by the International Atomic Energy Agency

REUTERS

Plokhy knows the consequences of such a nuclear disaster. In 1986, living in the city of Dnipro in eastern Ukraine, he remembers rumours starting to spread about an explosion at Chernobyl. “I went to the people I knew in the city administration but there was a huge blockade on the information,” he says. “The information we had was mostly coming from the Voice of America and BBC. We kept our children inside the apartment for most of that summer. My son was three years old and my daughter was two at that time. It was a very important event in my life.”

He became fascinated by the truth, which led to his landmark 2018 book on the disaster — Chernobyl: History of a Tragedy. The book in turn inspired the acclaimed HBO miniseries, Chernobyl, starring Jared Harris and Emily Watson.

“This new book is really a continuation of that search for the role of all things nuclear in our lives,” Plokhy says. “Some of the most really powerful missiles of the Cold War were produced in Dnipro, in a factory on the same street where I lived. My father-in-law worked there during the Cuban missile crisis.”

He also well knows the consequences of the current war. His cousin Andriy was killed in late 2022 when his army unit came under aerial bombardment near Bakhmut. “This is a war in which very often you don’t see your enemy,” Plokhy says.

Regimes such as Iran, he says, look to Ukraine as an example of why it is vital to have a nuclear deterrent. “The blow that was delivered to non-proliferation by this war is humongous,” he says. The war has sent a clear message that nuclear weapons are the best available guarantors of sovereignty. And the technological barriers to achieving such power are now low.

“Even small and poor countries such as North Korea can acquire the bomb if they are determined to do so.”

So what should the West do about Iran’s determination to acquire nuclear capabilities?

Here, Plokhy takes an unusual stance. He views the 2003 invasion of Iraq — and the disastrous consequences that unfolded — as a symptom of the West’s unfounded (as it turned out) fear of Saddam Hussein’s weapons of mass destruction.

“My position is that an Iranian nuclear bomb is a bad thing,” he says. “But it’s still not as bad as an all-out war and potential repetition of Iraq’s story. We should try to stop them from building nuclear bombs, using all means that we have, but short of an all-out war.”

He says the drive for nuclear non-proliferation is “wounded, but it is not dead”. And its future depends on what happens in Ukraine.

That future, in a twist of history, could be determined soon in Budapest, the very city where Ukraine agreed to give up its weapons three decades ago. There Donald Trump, buoyed by his success in brokering a ceasefire in Gaza, has agreed to meet Putin in an attempt to bring the Ukraine war to an end.

“If the West is united enough and the United States — the major power that forced Ukraine to give up its nuclear weapons — eventually finds a way to protect Ukraine, that will be a very different ending and a very different story and a very different lesson to learn,” Plokhy says.

“Non-proliferation, in its foundation, is very discriminatory and unfair. There is an exclusive club of nuclear powers which decides not to allow nuclear power to any other country. But it is something that, at the end of the day, can still work in the interest of the world as a whole.”

The Nuclear Age: An Epic Race for Arms, Power and Survival by Serhii Plokhy is published on Tuesday October 21