Nuclear threat: how the unthinkable became possible

For much of the Cold War, prospects of Armageddon filled the nightmares of statesmen and their peoples. During the past three decades, however, we have lived as if nuclear weapons had ceased to exist. In 1985, the U.S. and Soviet Union issued a joint statement that “a nuclear war cannot be won and must never be fought,” which seemed to point the way toward a much less scary world.

Instead, we have worried about terrorism, climate change, the Middle East, energy and mass migration. If humankind had a sense of humor about itself, we would laugh heartily about the manner in which Putin has turned on their heads the predictions of most of yesterday’s futurologists.

The Ukraine invasion has prompted me to dust down my collection of histories of the Cold War. Almost all the authors reach conclusions which state, or at least imply, that the peril of a nuclear apocalypse disappeared with the 1991 collapse of the Soviet Union.

Such a magisterial chronicler as Harvard’s Odd Arne Westad, writing in 2017, believed that we now inhabit a world in which “unlike the USSR, [Presidents Putin and Xi Jinping of China] are not likely to seek isolation or global confrontation. They will attempt to nibble away at American interests and dominate their regions … Rivalries, most certainly, which may lead to conflicts or even local wars, but not of the systemic Cold War kind.”

Westad might say that what is now happening in Ukraine fulfills his expectation: that Putin’s ambitions are limited to restoring what he sees as the lost glories of the Soviet Union, not to conducting a showdown with the West. Yet today’s Russian leader follows his Cold War predecessors in one significant respect: by repeatedly issuing nuclear threats.

At the ballet in Moscow in August 1961, for instance, Soviet leader Nikita Khrushchev launched a tirade at the British ambassador, Frank Roberts, about the consequences of a nuclear exchange. The respective sizes of the U.S. and USSR, he asserted, would enable both nations to survive. But Britain, West Germany and France would be obliterated on the first day.

He asked Roberts how many bombs would be needed to dispose of Britain. Six, hazarded the ambassador. Khrushchev pronounced him a pessimist, Roberts recalled: “The Soviet General Staff … had earmarked several score of bombs for use against the U.K.,” which suggested “that the Soviet Union had a higher opinion of the U.K.’s resistance capacity than the U.K. itself.”

Compare this to Putin, arguably a less rational player than Khrushchev (though it did not seem so to President John F. Kennedy). Before overrunning Crimea in 2014, the Russian president reminded his people — and, of course, the West — that his country “is one of the leading nuclear powers … It’s best not to mess with us.” 

Immediately before this Ukraine invasion, Putin warned the U.S.-led alliance of “consequences that you have never experienced in your history” if it sought to interfere.

No Western leader since 1945 has uttered such threats. But this is what Putin does. His purpose is, of course, to deter North Atlantic Treaty Organization military intervention in Ukraine, and he has been largely successful. If Russia did not possess its nuclear arsenal, it is possible, even probable, that the U.S., U.K. and other allies would have considered committing their own troops to Ukraine, as happened in South Korea in 1950.

It is unlikely that Putin would have dared to invade without the cover provided by his nuclear bombs. As the Soviet Union was falling apart in 1991, President Mikhail Gorbachev’s foreign policy adviser Anatoly Chernyaev observed to a British diplomat that it was only because his country had nuclear weapons that anybody was still taking it seriously.

This is a message thoroughly understood by totalitarian regimes bent on survival at any cost, such as North Korea, or pursuing imperial ambitions, as is Iran. And by the Russian Federation, a basket case in most respects.

Some people now argue that it was folly for Ukraine to give up its own nuclear weapons (inherited from the Soviet Union) following a 1994 Russian non-aggression guarantee that has proved worthless. Yet it seems unimaginable that Ukraine’s government would in any circumstances have threatened a neighbor with a nuclear weapon, far less fired one.

As for today’s Russia, Kremlin spokesman Dmitry Peskov delivered a chilling warning several weeks ago, speaking of how strategic missile test launches are at the discretion of the head of state: “You know about the famous black suitcase and the red button.”

Last week, Peskov said that his country would only use nuclear weapons if its very existence were threatened. He spoke in response to CNN interviewer Christiane Amanpour, who pushed him on whether he was “convinced or confident” that Putin would not use the nuclear option in Ukraine.

The word of Putin or his spokesman is, of course, worthless. It is certainly unlikely that Russia would launch ballistic missiles against the West: however unstable its president, he knows that this would provoke the obliteration of his own country.

If, however, Russia’s conventional campaign in Ukraine continues to falter, it is entirely plausible that the Kremlin will justify a use of weapons of mass destruction by claiming that Russia’s “very existence” is threatened by Ukrainian President Volodymyr Zelenskiy and his people, whom he has already accused of seeking to develop a nuclear “dirty bomb.”

Putin would most likely use chemical or biological weapons. But it also possible that he might explode a small nuclear device, conceivably as a demonstration, to convince the Ukrainians that they have no realistic choice save surrender.

The purpose of tactical nuclear weapons is to inflict devastating local damage on an enemy’s conventional forces, without causing drastic wider consequences that damage one’s own formations.

To grasp the relative power of “tac nukes”: the yields of the Hiroshima and Nagasaki bombs were measured at 15 and 21 kilotons, respectively. Today’s battlefield warheads measure between 0.3 and 5 kilotons, but almost all have adjustable yields up to 170 kilotons. (One kiloton creates destruction comparable to 1,000 tons of TNT.)

Russian doctrine has always favored “calculated ambiguity” about nuclear weapons use. Many of Moscow’s missile systems, such as the Iskander, with a range of 300 miles, have a dual conventional and nuclear capability. So does the Kinzhal air-to-ground hypersonic missile, which the Russians say they used in Ukraine on March 18.

A low-yield airburst of less than five kilotons detonated, say, over a Ukrainian armored brigade outside Kyiv, would generate a fireball, shockwaves and radiation that would obliterate the formation. To recall my first sentence, nobody knows how real the prospects are of the Kremlin making such a choice. But for years there have been reports that Putin is an advocate of resorting to battlefield nuclear weapons if a conventional campaign is going badly for his side.

Russia possesses 6,000 nuclear warheads of all kinds. This is more than half the entire global arsenal and compares with 4,000 U.S. warheads. Around 2,000 in the Russian stockpile are tactical weapons. Russia has never adopted the “no first use” doctrine.

Most of us recoil from the specter of any sort of nuclear explosion, which would be the first in a theater of war since August 1945. Once such a threshold is crossed by any country, it is likely to prove a watershed moment for humankind: other nations in conflict would follow suit.

We cling to a belief that even the deluded, mass-murdering Putin recognizes this. Yet I cannot forget that, before the 1962 Cuban Missile Crisis, both U.S. and British intelligence rejected the likelihood of Khrushchev deploying nuclear weapons in the Caribbean, because it would be at odds with the usual cautious strategic pattern of Soviet behavior.

John Hughes, who in 1962 was a senior official with the U.S. Defense Intelligence Agency, wrote in a later analysis of the crisis that the greatest barrier to developing strategic warning is “the tendency of the human mind to assume that the status quo will continue … nations do not credit their potential opponents with the will to make unexpected acts.” A year ago, how many of us believed Putin would unleash such a horror as his invasion of Ukraine?

Ever since Hiroshima, and even more since the Soviet Union tested its first nuclear weapon in August 1949, nations have been struggling to create rational strategies for superpower conflict in a world of nuclear weapons. None has been notably successful.

President Harry Truman fired General Douglas MacArthur in April 1951, mostly for appearing to advocate dropping an A-bomb on China. Presidents Dwight D. Eisenhower and Kennedy decisively rejected the almost deranged counsel of some of their armed forces brass, who were eager to exploit America’s then-overwhelming nuclear superiority.

Admiral Arthur Radford, who from 1953 to 1957 was chairman of the Joint Chiefs of Staff, was a strong supporter of MacArthur and committed to using America’s nuclear muscle to impose its will, especially against China. Air Force General Curtis LeMay, a strident voice in the Cuban Missile Crisis, served out a 1961-65 term as supremo of his service, despite insistently proclaiming his enthusiasm for a showdown with the Soviet Union in which he was confident that the U.S. would prevail.

By contrast, in 1953 Eisenhower, though sometimes branded a hawk alongside his Secretary of State John Foster Dulles, said that he found the prospect of nuclear war so terrible that it posed the problem of “how much we should poke the animal” — the Soviet Union — “through the bars of the cage.”

In the context of Ukraine, it is striking to recall Eisenhower saying in 1956, when the Soviet Army crushed the Hungarian Uprising, it is “a bitter pill for us to swallow, but what can we do that is really constructive?” Nuclear superiority meant nothing unless the U.S. was prepared to threaten to bomb Moscow and mean it, which mercifully Ike was not.

Instead, he sought to calm the Russians — then, as now, in a dangerous mood. As Dulles put it, the U.S. had “no ulterior motive in desiring the independence of satellite countries” and did not “look on these nations as potential military allies.” Perversely, and in some degree as we see with Russia in 2022, American might and the old Soviet Union’s relative weakness did nothing to empower the president to embark on military action, without risking nuclear war.

Through the past half-century, every nuclear nation has wrestled with the question of whether it might be possible to use tactical weapons on the battlefield without triggering escalation toward mutual annihilation. James Schlesinger, a former RAND Corporation analyst who became secretary of defense in 1973, commissioned studies on limiting conflict. He also expanded and modernized America’s tactical nuclear arsenal.

These measures alarmed the Soviets, who thought he was seeking a path toward abolishing “mutually assured destruction,” the foundation stone of deterrence.

Four years earlier, a Russian officer, Colonel A.A. Sidorovsky, published a widely discussed book entitled “The Offensive,” arguing that any first use of nuclear weapons on the battlefield, whatever the state of the conventional struggle, would mark a dramatic shift in the character of war. Once such weapons had been employed by either side, they were bound to become the main means of destroying the enemy. In other words, escalation was inescapable.

That assumption has since formed the basis of almost all military thinking, though the major powers maintain tactical nuclear weapons. Admiral Charles Richard, head of U.S. Strategic Command, recently told the Senate Armed Services Committee that his planners had for years been analyzing “limited nuclear use in a conventional aggression scenario” and that “there is a significant class of theater threats that we’re going to have to rethink potentially how we deter that.”

The U.S. has invested heavily in supposedly more “usable” low-yield weapons such as the W76-2 and B61-12, a policy some critics condemn as promoting an unwelcome trend toward capability for war-fighting, rather than deterrence.

Melissa Hanham of Stanford’s Center for International Security and Cooperation expressed a widely-held opinion when she said: “You can’t just nuke someone a little bit … once you start a nuclear war, it’s on.” As defense secretary in 2018, General James Mattis told the House Armed Services Committee: “I don’t think there is any such thing as a tactical nuclear weapon. Any nuclear weapon used at any time is a strategic game changer.”

Yet we cannot be confident that Putin agrees. His playbook could be telling him what a similar volume urged to MacArthur back in 1951. Ukraine now, like China then, lacks any capability to respond to the detonation of a nuclear weapon. A strike might be capable of transforming the battlefield within minutes in Russia’s favor.

Putin despises the West’s supposed weakness, decadence and sensitivity about casualties. If he uses any sort of weapon of mass destruction in Ukraine, he may calculate that President Joe Biden — despite his strong warning in Europe this week — would still hold back from escalation toward a superpower showdown.  

It seems cause for concern that the U.S. military reported this week that it found difficulty getting Russia’s top generals to accept their calls, for routine safety dialogue. If Putin’s war continues to stall, he could decide: Why not a WMD? And unlike with MacArthur in 1951, there is no Harry Truman to fire him.

Max Hastings