The Path To The Next Use Of A Nuclear Weapon Is Right Before Our Eyes

Whether a nuclear weapon might again be used by one nation against another is a question that has haunted the world for nearly a century.

Cold War doctrine argued that such an act would be deterred by the threat of mutually assured destruction, known by its ironic acronym, MAD.

A related concept also played a part in such deterrence—the “nuclear taboo.” This holds that any such attack is so morally abhorrent, so destructive to the aggressor’s global standing, so able to stain forever the leader or nation that carried this out, as to dissuade any thought of pursuing a first strike.

Three-and-a-half decades after the Cold War, in a new era of growing nuclear arsenals, it makes sense to ask whether such concepts still have force. There are reasons to conclude that they don’t.

Distance Of Time Makes The Mind Grow Softer

In my own discussions with nuclear security experts (who, unsurprisingly, asked not to be named for this article), time has been a frequently mentioned factor. It is nearing a century since the atomic bombings of Hiroshima and Nagasaki, with an ever-growing majority of people worldwide never having experienced the looming shadows of peril cast by these terrible events and, not long after, the Cuban Missile Crisis.

Trepidation, these experts maintain, is today devoted to the seemingly more imminent threats of climate change, AI, and pandemics. Even such realities as the collapse of nuclear arms control, North Korea acquiring the bomb, and the “modernization” of national nuclear arsenals have failed to rouse public or political concern to a consistent degree.

After The Cold War

In the 1980s, US and Soviet arsenals together reached a total of over 70,000 nuclear warheads. These included “strategic” weapons, with explosive yields of 100 kilotons to megatons and longer-range targets, and “tactical” weapons, with smaller yields of less than a kt to 50 kt and short-range intended use. For comparison’s sake, the “Little Boy” bomb that destroyed Hiroshima had an estimated 15 kt yield.

As the Soviet Union broke apart in 1991, President George H.W. Bush unilaterally announced the elimination of virtually all US tactical nuclear weapons from Europe. Soviet leader Gorbachev reciprocated, and a new period of major downsizing of stockpiles began.

Under Vladimir Putin, however, Russia’s “modernization” program has returned tactical weapons to around 2,000, roughly 10 times the number now possessed by the US. This appears a strategy meant to deter NATO’s superior conventional forces.

Yet, experts worry that these “battlefield” weapons can be viewed by certain leaders as having a lower threshold of use. This could mean, for example, they are integrated with conventional arms into plans for military action, offensive or defensive.

In November 2024, the Kremlin officially revised its own nuclear doctrine to include first use against any attack perceived as threatening to Russian sovereignty or territorial integrity. In fact, in its large-scale Zapad military exercises, held every four years, Russia has rehearsed first use of nuclear weapons for two decades. The lowering of the country’s nuclear use threshold in 2024 was viewed by analysts as especially troubling, given that “Russia already had the lowest threshold for nuclear weapons use in the world.”

What Have We Learned From The War In Ukraine?

Russia’s invasion of Ukraine in 2022 and the subsequent years of war have brought two reasons for concern along these lines.

First, after Russian forces became bogged down by weather and heavy resistance, Putin broached the idea with Xi Jinping of using a nuclear weapon to alter the situation. According to then-Secretary of State Anthony Blinken, Xi rejected the idea emphatically.

Blinken noted the US had become deeply worried the chances of such use might have gone from “from 5 to 15 percent.” In fact, the CIA had raised the probability to no less than 50%, if Ukrainian combat successes continued. This was based on intercepts of high level Russian military conversations, which included mention of specific units who would be involved in readying the weapons.

That things went this far suggests that employing a tactical weapon in the face of major conventional defeat is an operating policy. While this has been discussed by analysts for decades as a possible element of Russian strategy, a part of “escalate to de-escalate” posture, the above appears to show it is now operational.

Whether Putin ordered an actual plan of tactical weapon use be drawn up, we may never know. In the event, the combat situation came to shift in Russia’s favor, removing the immediate motive. The lesson is that a limited nuclear strike, whether for lethal or fear-generating aims, will be back on the table should Ukraine again gain the upper hand, with or without NATO’s help.

A Second Lesson Unveiled

The other example is no less worrying.

An early objective for Russian troops was to occupy the Chernobyl nuclear plant. This involved a drone strike that seriously damaged the confinement structure over Unit 4, the reactor that exploded in 1986 and that remains dangerously radioactive.

A month later, Russian troops seized control of the Zaporizhzhia Nuclear Power Plant, firing on its structures and damaging buildings. Once the plant was captured, moreover, it was made a forward operating base for attacks on nearby towns. Russain forces planted anti-personnel mines within the plant compound and continued employing it as a shield against Ukrainian counterattack for more than a year. Though all six reactors were in cold shutdown, risks have remained for pumps working to cool reactor cores and spent fuel.

These pumps require 24-hour power. Yet multiple outages have occurred under Russian occupation, leading to repeated use of emergency diesel generators. In June of 2023, Russian troops blew up the nearby Kakhovka Dam, causing massive flooding, environmental impacts, and a temporary end to the flow of cooling water for the Zaporizhizhia plant.

Since 2023, Russian missile and drone attacks have repeatedly targeted electricity substations providing power to Ukraine’s three other nuclear plants—the South Ukraine, Khmelnitsky, and Rivne. Teams from the International Atomic Energy Agency, the UN nuclear watchdog, have regularly visited Zaporizhizhia and more recently these other plants, describing the situation as one where “dangers to nuclear safety continue to be very real and ever-present.” Director General Rafael Grossi in his most recent statement again calls for “maximum military restraint in the vicinity of nuclear facilities.”

Half-Steps To First Use?

Together, these examples tell us that the powers of nuclear deterrence have grown significantly weaker. The idea of a nuclear dimension to warfare no longer commands the preventive dread and unfeasibility it once did. While the focus above has been Russia, it should be understood more broadly.

North Korea ’s advanced nuclear and missile capabilities, its development of tactical weapons, its new military alliance with Russia, and its designation of South Korea as a permanent “hostile state” cannot be ignored in this context. Neither can the buildup of tactical weapons and rejection of a no-first use policy by Pakistan nor, despite recently re-affirmations, the ambiguity introduced over the past decade to India’s own NFU posture.

Such realities are heightened by the general growth of nuclear stockpiles at a time when arms control agreements have virtually disappeared without any replacements in sight.

Concerns about nuclear first use today tend to highlight the possibilities of crisis-driven escalation in a regional war, misperception or miscalculation of an adversary’s intentions, and command and control failures, possibly involving digital technology.

The half-steps taken by the Kremlin toward nuclear use—either in the form of a battlefield weapon or a power plant turned into a giant “dirty” bomb—provide a different though related possibility. Changes not only to norms but to the psychology governing nuclear weapons, diminishing the imagination of disaster and rendering the unthinkable more thinkable, are also a core risk for the decades ahead.