Shadow of Hiroshima: 78th anniversary brings current nuclear climate into focus

For example, in March 2023, the former Russian President and current deputy secretary of Russia's Security Council stated, "Every day when Ukraine is provided with foreign weapons brings the nuclear apocalypse closer."

With Russia possessing the largest arsenal of nuclear weapons in the world, such rhetoric underlines the possibility that the war in Ukraine could yet provoke another Hiroshima.

A nuclear timeline

The history of nuclear weapons after Hiroshima and Nagasaki is a cause for both fear and optimism. On the one hand, the superpowers raced to develop more and more destructive weapons, while several medium and emerging powers emulated them and produced their own arsenals.

On the other hand, a concerted effort was also made by the global community, and later, the superpowers themselves, to regulate and restrict nuclear proliferation, prompting notable disarmament – even if significant numbers remain.

As the Cold War heated up, Washington and Moscow engaged in a nuclear arms race, initiated in 1949 when the Soviet Union conducted their own nuclear tests, to America's alarm. Acquiring military bases across the world – and the development of intercontinental ballistic missiles and nuclear submarines – gave both the ability to launch nuclear attacks anywhere in each other's territory.

More and more warheads were built to outflank each other. In the mid-1960s, America peaked at over 30,000, at a time when the Soviets had barely 5,000. The USSR then caught up, as America slightly reduced its arsenal, boasting 40,000 to Washington's 24,000 by the late 1980s.

Meanwhile, Britain, France, and China each developed their own nuclear capabilities. This occurred in 1952, 1960 and 1964 respectively – though none ever built more than a few hundred warheads.

The 1960s also saw Israel develop nuclear technology, though it has never openly admitted to possessing atomic weapons. It is also widely believed that Israel collaborated with Apartheid South Africa to help it build six nuclear weapons in the 1980s. In 1974 India tested its first nuclear weapons, while its great rival Pakistan followed suit in 1998. North Korea became the latest state to proliferate in 2006.

Though the proliferation of weapons concerned many, it might have been far worse were it not for the Treaty on the Non-Proliferation of Nuclear Weapons, which came into effect in 1970. The treaty agreed that no more states beyond the five that possessed nuclear weapons at the time of the treaty's creation, 1967, would be allowed to develop them.

As of 2016, 191 countries had signed up. Only four UN members chose not to join; unsurprisingly, they were the states that went on to build their own nuclear arsenals: Israel, India, and Pakistan, plus the new state of South Sudan. North Korea initially signed but withdrew in 2003.

Most states agreed to limit the spread of nuclear weapons. During the Cold World, the superpowers also agreed to freeze and later reduce their arsenals. The SALT I and SALT II treaties in the 1970s saw the USA and USSR limit the number of Intercontinental ballistic missiles they each had. The late 1980s and early 1990s (as the Soviet Union declined) saw more treaties emerge that further limited long-range missile numbers.

After several other loose agreements, 2010 saw the New START treaty, which reduced Russia and America's deployed nuclear weapons by about half. These agreements, alongside South Africa's decision to disarm in the 1990s, and the removal of thousands of Soviet missiles from the now-independent republics of Ukraine, Belarus and Kazakhstan, means the world currently has the smallest number of nuclear weapons since the late 1950s.

Estimates from the Federation of American Scientists suggest that Russia currently has 5,899 warheads, the US has 5,244, China has 410, France has 290, the UK has 225, Pakistan has 170, India has 164, Israel has 90 and North Korea has 30.

Together, the US and Russia possess over 90% of the world's nuclear weapons.

Russian threats

Even though the number of warheads is now far lower than the extreme Cold War levels, each nuclear power still possesses more than enough firepower to obliterate their enemies several times over.

As such, the willingness of Putin and other Russian officials to include nuclear weapons in the discussion of the Ukraine war has understandably alarmed foreign governments, especially in the West.

In September 2022, seven months after the invasion of Ukraine – and with Russia forced to retreat and initiate a full mobilisation – Putin stated that Russia had "lots of weapons to reply" to what he called Western threats on Russian territory. He further assured Western leaders that this was "not a bluff."

Since then, Putin has not backed down or moderated his stance.

In February 2023, he announced Russia will halt its participation in the New START treaty, the last significant nuclear arms control treaty with America. In June, Belarus president Alexander Lukashenko declared that Russian tactical nuclear weapons had been deployed in his country – rearming Belarus for the first time since the early 1990s.

These weapons — said to be three times more powerful than the Hiroshima bomb — were designed for battlefield deployment, which poses a clear threat to Ukraine. The aggression was directed beyond just Kyiv.

In March, when the UK supplied Kyiv tank shells made with depleted uranium, Putin stated, "Russia will have to respond accordingly, given that the West collectively is already beginning to use weapons with a nuclear component."

Though he didn't elaborate further, many interpreted this as an indicator that he would consider firing nuclear weapons at Britain. 

Putin's bluff?

How serious are such threats? US President Joe Biden has seemed conflicted on the question, stating in June 2023 that the threat was "real," while then stating a month later that, there is "no real prospect of Putin using nuclear weapons."

Such ambiguity is unsurprising given a similar split among experts and analysts. On the one hand, several specialists on Russia and nuclear weaponry have argued that, for all his rhetoric, Putin is most likely bluffing.

Valeriy Akimenko of the Conflict Studies Research Centre argues that "Russia's nuclear weapons would only actually be used in extremis." Surveying various experts in a column for the Chatham House think tank, he concludes that Russia primarily sees its nuclear weapons as a political defensive deterrent, not an offensive battlefield option.

He similarly cites one analyst, Olga Oliker, suggesting that Russia is leveraging its status as a nuclear power to force the West to back down. Despite Putin's statements, she says, there is little evidence Russia has lowered its threshold for nuclear use since the Ukraine war began.

Akimenko does not argue that there is no danger, however. She notes that the Russian military doctrine shifted in the late 1990s from 'no first use' to 'assured first use if Russia's survival is at stake.'

If Putin truly believes Russia's survival is under threat, he may, therefore, in theory, consider nuclear deployment even before being attacked by an enemy nuclear weapon.

On the other hand, some analysts are more concerned that Putin may be serious about his threats. Lauren Sukin from the London School of Economics argues that Putin's character means the West should take the threats seriously.

As with North Korea's Supreme Leader Kim Jong Un, Putin is a highly personalistic leader surrounded by yes men with few checks on his power. Like Kim, Putin is "deeply anxious about their legacies and beholden to unlawful and, increasingly, unrealistic foreign policy ambitions."

Sukin argues that this deep paranoia makes Putin dangerous, describing it as "the sort of high anxieties in Moscow that could lead to risky decision-making, whether nuclear in nature or not." In some ways, this reflects Akimenko's point about the possibility of pushing the nuclear button if Russia's survival is at risk.

If Putin is indeed as paranoid and anxious as Sukin argues, he may perceive a reversal in Ukraine as a danger to the very existence of Russia, even if this may not be the case.

Current climate

Much, then, may rest on the character of Vladimir Putin. He may simply be using the nuclear threat to maximise his leverage, with no real intention of launching an atomic attack in Ukraine or elsewhere. But he may genuinely feel that the West's support for Kyiv poses an existential threat to Russia, and therefore be willing to pre-emptively use nuclear weapons.

While this may seem a terrifying prospect, in many ways, it replicates the situation for much of the Cold War. Soviet leaders (and American presidents) possessed the power to launch nuclear attacks, and many decisions depended on their own character. More hawkish figures than Khrushchev or Kennedy, for example, may well have pushed the button during the Cuban Missile Crisis.

Of course, such a prospect has, for years, prompted many to urge further nuclear disarmament. While notable progress was made in the later years of the Cold War and in the 1990s, that trend now appears to be in reverse.

Indeed, the 2023 G7 meeting was held symbolically in Hiroshima. The Japanese Prime Minister Fumio Kishida, aware of Putin's threats, urged his fellow leaders to recommit to nuclear disarmament. Yet, despite Biden and other leaders being clearly moved by the haunting shadows of Hiroshima's Peace Memorial Park, Kishida made little headway.

Confronting China and helping Ukraine defeat Russia took priority and questions of nuclear disarmament were largely overshadowed. But Japan was the one country to have suffered a nuclear attack and thus understood better than any that more controls and limits are likely needed to avoid future nuclear showdowns, such as the one looming over Ukraine.