Would Putin use a small nuke? Look to the US’s troubled nuclear history.

Russia has about 2,000 small nuclear weapons, known as tactical nukes. But most of the world probably hadn’t been thinking about them until Vladimir Putin reached new desperate lows in the invasion of Ukraine. “This is not a bluff,” he said upon the mass mobilization of Russian troops last month. “And those who try to blackmail us with nuclear weapons should know that the weathervane can turn and point towards them.”

The Russian president has issued veiled threats from the early moments of the war, but his more overt recent threats led US President Joe Biden to say that the risk of nuclear “armageddon” is the most acute since the 1962 Cuban missile crisis.

Now the question that permeates all discussions of Russia’s war: Would Putin break with international norms to strike Ukraine or its partners with a tactical nuclear weapon? The US would likely respond with a conventional weapon, directly attacking Russia, and the conflict would almost surely escalate. But what has largely been a proxy war between the two countries could turn into something altogether more dangerous.

Since the onset of Putin’s invasion, the US media has at times painted him as a madman and an irrational actor, in large part because of that threatening language suggesting he might use nukes.

But the history of tactical nuclear weapons during the Cold War offers a more complex story that is important to contextualizing the current crisis. After World War II, it was the United States, in fact, that first developed an arsenal of small-yield nuclear arms for the battlefield, not to destroy a whole country and win a war, but to win a specific tactical advantage or battle. As recently as the Vietnam War, generals urged the president to grant them authority to deploy tactical nukes in combat. In 2002, George W. Bush’s leaked nuclear strategy held out the preemptive use of weapons of mass destruction in seven countries. It remains shocking that Bush’s team reportedly sought “greater flexibility” in the threshold for using nukes, “in the event of surprising military developments” or “against targets able to withstand non-nuclear attack.”

Though the likelihood of nuclear weapons being used in Europe today remains low, the tenor of threats has reached an intensity that recalls an era when the possibility of nuclear war was much more present.

How the US thought about tactical nukes in the Cold War

The US never launched tactical nukes into the battlefield. No country has. But moments in which their use was seriously considered are worth revisiting.

There were two broad categories where officials considered them early in the Cold War. One was should the US come into direct conflict with the world’s other superpower. Initially, the US saw itself as facing a Soviet threat that had superior conventional capabilities. Tactical nuclear weapons were a way to adjust the military balance in Europe to NATO’s favor in the ’50s and ’60s, to compensate for NATO’s vulnerability.

The nukes were designed to target Soviet tank regiments. In an era when weapons were not as precise as today’s missiles, the nuclear yield compensated for inaccuracy.

“The US invented and deployed an amazing array of nuclear weapons that were intended for battlefield use,” Gary Samore, the senior White House official for countering nuclear proliferation in the administrations of Barack Obama and Bill Clinton, told me. “The situation now in Russia is very much the reverse, but the logic is the same. The Russians find themselves losing the war conventionally. And because of that, they could consider the use of tactical nuclear weapons as a way to compensate for their conventional weakness.”

US Army/Getty Images

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The smallest of them was the Davy Crockett, which could be moved on a portable launcher and whose missile contained a small nuclear warhead that could be fired a short distance, about 2 miles. Compared to the 15,000 tons of TNT yield of Little Boy, the bomb the US dropped on Hiroshima in 1945, the Davy Crockett’s yield was indeed small, similar to 20 tons of TNT.

“The dark humor was that the blast radius was bigger than the range,” Stephen J. Flanagan, a RAND political scientist who worked in the Clinton and Obama administrations on nuclear strategy, told me. “It sounds kind of bizarre now, or if you’re a fan of Kubrick’s Dr. Strangelove, but there was this enormous fear at the time that there was this gross imbalance, and that the only way that the United States could counter the extensive, massive conventional military capabilities of the Soviet Union and the Warsaw Pact allies was through reliance on nuclear weapons.”

But that evolved into thinking about the collective strength of a nuclear arsenal, and was less focused on deploying a singular bomb on a hypothetical battlefield in Eastern Europe. President Dwight Eisenhower’s administration created the doctrine of massive retaliation, using nuclear weapons as a deterrent against the Soviet Union, and in the process popularized the slogan “more bang for the buck.”

The second set of circumstances was the proxy wars America fought around the world. The US considered dropping nukes on the battlefield during the Korean War, in 1950. When China joined North Korean troops and drove US forces south from the Yalu River, separating Korea and northeast China, Gen. Douglas MacArthur requested permission from President Harry Truman to launch nuclear weapons against Chinese military targets. “Truman rejected that because Korea was seen as a limited war,” Samore, who is now a professor at Brandeis, told me.

In 1958, the US again came close to using nuclear weapons. As Chinese communist forces sought to take over Taiwan, Secretary of State John Foster Dulles and senior military leaders drafted plans to strike them with a nuclear weapon. Ultimately, President Eisenhower decided against it.

Questions endure about whether, four years earlier, Dulles offered a French counterpart two atomic bombs as their forces were getting clobbered by Ho Chi Minh’s forces in southern Vietnam.

As the Vietnam War deepened, there was further consideration of nuclear first use. In 1968, when the US was struggling in battles against Vietnamese insurgents, Gen. William Westmoreland sought to have nuclear capability. “Should the situation in the DMZ area change dramatically, we should be prepared to introduce weapons of greater effectiveness against massed forces,” he wrote in a cable.

The Joint Chiefs of Staff also considered “employing atomic weapons, whenever advantageous,” in the case that China intervened in the war, according to a memo that Eisenhower signed off on and that later surfaced in the Pentagon Papers.

It was part of a debate emerging as to whether US commanders in the field in Vietnam should have the power to use tactical nukes, and military leaders like Gen. Curtis LeMay and Adm. Harry Felt argued in favor.

President Lyndon B. Johnson repeatedly dismissed the nuclear option. “The president and I were shocked by the almost cavalier way in which the chiefs and their associates, on this and other occasions, referred to, and accepted the risk of, possible use of nuclear weapons,” wrote former Defense Secretary Robert McNamara in his memoir In Retrospect. He called using nukes against China, itself a nuclear power, “almost surely an act of suicide.”

Yet McNamara was at times willing to make a nuclear bluff, as Brown University scholar Nina Tannenwald has noted. “We’d use whatever weapons we felt necessary to achieve our objective,” McNamara said in an April 1965 background briefing to reporters about Vietnam.

That captures the slowly developing shifts in the US’s thinking about nuclear weapons in that decade. Tannenwald argues in her 2007 book The Nuclear Taboo that “political and normative considerations” made tactical nukes “less usable than ever.” Republican Sen. Barry Goldwater, who ran for the presidency in 1964, advocated for their use — and it may have contributed to him losing the race. “The stakes are too high,” said the voiceover of LBJ’s famous 1964 daisy-plucking campaign ad that depicted the extreme dangers of Goldwater’s nuclear saber-rattling. Yet if Goldwater had won, he very well may have approved the use of tactical nukes in Vietnam.

In the meantime, a young professor named Henry Kissinger came to prominence with his bestselling 1957 book Nuclear Weapons and Foreign Policy, which picked apart Eisenhower’s doctrine of massive retaliation and argued that a “limited nuclear war” could be won. Kissinger, when in the Nixon administration and after, recanted that preference. Last month, he told the Council on Foreign Relations, “we cannot permit nuclear weapons to become conventional weapons.”

Much of Washington’s brazen attitude to using nuclear weapons in the earlier part of the Cold War relates to a different way that many policymakers then thought about the weapons. James Acton, a nuclear expert at the Carnegie Endowment for International Peace, explained that the distinction between tactical and strategic nuclear weapons didn’t emerge until the ’70s amid the arms control negotiations with Russia.

“This division between strategic and non-strategic crystallizes pretty late,” Acton told me. “The US military genuinely planned to use nuclear weapons in the Cold War as if they were some form of super artillery” — very large conventional weapons that could be deployed in the same way as conventional weapons.

“There is nobody in the US military or civilian defense sectors who really thinks about nuclear weapons as being super artillery anymore,” he told me. “I don’t think Russian political leadership — I mean Putin, personally — thinks about nuclear weapons as being super artillery.”

Apocalypse Now?

The US had 7,000 tactical nukes in Europe at one point, but “the United States largely pulled out of the tactical nuclear weapons business after the end of the Cold War,” says Hans Kristensen of the Federation of American Scientists. “There was some fanciful dream about the utility of nuclear weapons in the early phases. And later, they became much more cautious about it. It sort of became a taboo.”

Today, the US has a small arsenal of tactical nukes dispersed among five bases across Europe and Turkey.

Tarik Tinazay/AFP via Getty Images

At the end of the Cold War, in 1991, President H.W. Bush withdrew most of the US’s tactical nuclear weapons from Europe. But for various reasons, tactical nukes were never a part of major START arms control treaties between the US and Russia. Experts told me that tactical nukes, because they are small and often can be delivered on conventional warheads, are tough to monitor and verify. For Moscow, tactical nukes were seen as closer to being a conventional weapon, and these major treaties were concerned with long-range capabilities. “We did try to include tactical nuclear weapons, and the Russians rejected it,” Samore said.

But there still have been moments before Russia’s invasion of Ukraine that harked back to the dangers of the Cold War. In 2002, as part of a nuclear posture review, the George W. Bush administration drafted plans for the use of nuclear weapons against China, Russia, Iraq, North Korea, Iran, Libya, and Syria — not just in the case of one of those countries using a nuke, but “in the event of surprising military developments.” In Le Monde Diplomatique at the time, French author Pascal Boniface called it the Strangelove doctrine, writing, “never, until now, has the US proposed to pull the nuclear trigger not just first, but without prior provocation.”

President Trump, for his part, withdrew from the landmark 1987 Intermediate-Range Nuclear Forces treaty, the only pact governing tactical nuclear arsenals with Russia. During the Trump administration, the US military once again began saying that it was necessary to have some low-yield and tactical nuclear weapons to play that tactical nuclear weapons game with the Russians. “That was a step back from what US policy had been,” Kristensen said.

With Putin’s threats against Ukraine comes a new calculus for how the small guild of nuclear experts sees a possible resolution. Samore’s concern is that Putin would use tactical nuclear weapons not as a military instrument but as a coercive measure — “In other words, to say to Kyiv, ‘Unless you surrender or accept our terms for a ceasefire, we’re going to keep using nuclear weapons in an escalating way.’”

The precedent for that is, worryingly, the US’s own use of nuclear coercion in Hiroshima and Nagasaki, the only times that nukes have been used in war.

For Daniel Ellsberg, the whistleblower who leaked the Pentagon Papers and is now 91, Putin is already doing that, “using” his nuclear arsenal through his threats. The United States “used those threats in the past repeatedly, in maintaining our sphere of influence around the world, right up to the borders of the old Soviet Union or of China,” Ellsberg told an interviewer in April. “The Russians have gone back to Eisenhower’s old New Look doctrine, massive retaliation doctrine, or reliance on nuclear threats, to compensate for the shortcomings of their conventional forces.”

As Ellsberg put it, “They’re doing what we did in the fifties and the sixties.”