Atomic Pulse

Blundering into a nuclear war in Ukraine: a hypothetical scenario

NTI experts believe that the most likely use of nuclear weapons in any scenario would be unintentional—that humanity would blunder into a nuclear war. Vladimir Putin’s invasion of Ukraine is a prime example of a regional conflict that could inadvertently escalate beyond any of the protagonists’ expectations. History is replete with similar instances of humanity stumbling into devastating conflict.

What follows is a hypothetical scenario illustrating just one possible pathway to a global, catastrophic nuclear war.

The accident

Two Ukrainian SU-27 fighter aircraft fly southwest from Ukraine to make an emergency landing in Romania, after fleeing Russian forces. Though on alert, the commander of the Russian anti-aircraft unit operating S-300 surface-to-air missile (SAM) systems in southern Ukraine and his soldiers have barely slept over the past few weeks. The 21-year-old conscript monitoring the system’s radar identifies the two planes among a number of other aircraft flying over the Black Sea. He points out the blips on his screen to his sergeant, who quickly reports what they are seeing to their commander.

The Ukrainian fighters are fast and will be out of range in only a few minutes. The Russian SAM commander gives the order to destroy them and listens as his crews go through their firing sequences. As he wipes the sleep from his eye, he looks in the direction of the launchers and sees two sets of missiles go in completely different directions. He freezes and asks his fire control officer to read back their target numbers. Remembering the downing of Malaysia Airlines flight MH17 over Ukraine back in 2014, the blood drains from his face.

One Ukrainian fighter lands safely in Romania—but his wingman is nowhere to be seen. One set of Russian missiles did its job.

The second set of missiles hit a U.S. Air Force E-8 JSTARS reconnaissance aircraft that had been monitoring the conflict from the Romanian border, killing all 34 crewmembers. Video of the crash site near the Black Sea emerges on social media and tops the world’s newsfeeds. At massive demonstrations in Western capitals, images of the crewmembers become icons representing NATO’s first fallen heroes in this war.

All Western countries immediately close their embassies in Moscow and expel Russian diplomats in an initial protest. The U.S. president must decide how else to respond. Given the explosive domestic pressure to act forcefully, hawks and doves all agree that the United States would be justified in invoking Article 5 of the NATO founding treaty. That would obligate all NATO members to come to its defense. But was the attack intentional? If not, maybe he could find a way to deescalate the situation, but with all the disinformation, it is impossible to know. And even if it was intentional, is escalation worth the potential consequences? Russia’s president had just issued an ominous statement, saying “Whoever tries to interfere with us … should know that Russia’s response will be immediate and will lead you to such consequences that you have never experienced in your history,” a thinly veiled threat of nuclear weapons use.

The miscalculations

Across the battle lines in the Kremlin, Russia’s leader, furious that this accident might derail his plans to continue advancing into Ukraine, assumes he will face a strong NATO military response after seeing the outrage emanating from Western capitals. He knows, however, that it will take some time for the bulk of the American military to arrive on European soil.

Sequestered in the Kremlin with no members of his security council willing to contradict him, he decides to strike first—perhaps a sharp escalation early on will convince NATO not to pick a fight in the first place. He plans to launch a salvo of conventionally armed cruise and ballistic missiles—most previously banned under the now-defunct Intermediate Range Nuclear Forces Treaty—against major NATO military installations in Eastern and Central Europe and then make his demands.

The cyber-nuclear nexus

But first, to ensure those Russian missiles reach their targets, NATO’s missile defenses must be rendered useless by blinding them. To accomplish this, Russian anti-satellite missiles fire, turning American early warning satellites into space debris. Then, Russia’s infamous cyber Unit 74455 activates malware—which had lain dormant and undetected in U.S. and NATO military computer systems since the Solar Winds hack—and executes a cyberattack on NATO’s land-based missile detection systems in Europe.

As his preemptive attack unfolds—the cruise and ballistic missiles had not even been launched yet—the Russian president feels confident NATO will get his message: Stay out of Ukraine and this war will not have to escalate any further. But that is not how it was perceived in Washington. Unbeknownst to Moscow, the cyberattack spreads farther than its intended targets, freezing U.S. Strategic Command’s (STRATCOM) command and control systems, cutting off its communication with U.S. nuclear-armed submarines worldwide, and forcing intercontinental ballistic missile (ICBM) crews to scramble to redundant analog systems. These attacks can only mean one thing: a Russian nuclear strike would be next.

The Russian leader knows the Americans never adopted a “No First Use” or “Sole Purpose” policy—and he may not have believed them if they did—but he had not expected his limited attack to trigger such a massive response. Why did the Americans go to DEFCON 1, scrambling their nuclear-capable bombers and airborne command posts?

But this isn’t the only complication. Governments are no longer the only protagonists in 21st century warfare, and the actions of nonstate actors further aggravate an already tense situation. Witnessing the anti-satellite missile attacks, the worldwide hacking collective called “Anonymous,” already “at war” with Russia, responds in kind, taking Russian satellites offline and triggering numerous false alarms. Although they had publicly said such an action would amount to an act of war, the Russian president’s advisers’ call for restraint. In an increasingly paranoid state, he disagrees. The United States must be launching a nuclear first strike. This seems insane—would they not know how this would force his hand? Regardless, there is nothing to be done about it now.

The short decision window

In Washington, the U.S. president is rushed to the Presidential Emergency Operations Center along with his military aide (who carries the “nuclear football”) and what members of his cabinet are available. The STRATCOM Commander appears on screen and provides his assessment that, although he cannot confirm incoming missiles without functional satellites, STRATCOM’s artificial intelligence models say all indicators point to Russia launching its ICBMs in a nuclear first strike against the United States homeland.

He goes on: “Right now, hundreds of Russian ICBMs are likely hurtling over the North Pole towards our ICBM silos, airbases, and ports to destroy the U.S. nuclear arsenal. Once our nuclear deterrent is greatly reduced, Russia will be able to make any demand with near impunity. We can’t stop the incoming missiles, but we can get our ICBMs airborne toward their targets in Russia before they are destroyed. We have about seven minutes until they’re hit. You need to decide now: Use them or lose them.”

The president pauses, contemplates the gravity of the situation he is faced with, wonders how it could have come to this, and gives his final orders.

The nuclear effects

In Moscow, the Russian president makes his decision. He executes a countervalue strike on NATO cities. Since the American nuclear weapons were already on their way, he did not need to use any Russian warheads on American ICBM silos, submarine ports, and bomber bases where U.S. nuclear weapons were held—or so he thought. In fact, American ICBMs had never left their launch tubes—the U.S president had decided not to launch them until he had more information.

Over the course of the next hour, 82 million Americans are killed with allied countries faring similarly. Most die instantly, while more will die of radiation poisoning over the coming days and weeks. Those who survive will have chronic health problems for the rest of their shortened lives, and their children will likely be born with genetic defects. The sheer volume of burned earth and urban terrain sends massive volumes of ash into the atmosphere and causes a “nuclear winter,” greatly diminishing the amount of sunlight on Earth, impacting global food supplies and indirectly leading to starvation that causes untold more deaths. Progress on nearly every human endeavor from reducing poverty to combatting disease is set back tens if not hundreds of years. This is to say nothing of the many other severe, lasting global consequences, which collectively have the potential to disrupt the trajectory of human civilization and threaten its long-term survival.


This is a purely hypothetical scenario. At any point in the story, key actors could have made different choices, leading to different outcomes. But the point stands that in the fog of war, rational people can make critical errors and catastrophic events can unfold. In addition to this scenario, there are countless equally plausible—and maybe even more likely—pathways to possible use of nuclear weapons in other parts of the world. Though no country has detonated a nuclear weapon in conflict since 1945, nine countries currently possess an estimated 12,705 nuclear warheads. Humanity has been lucky thus far, but how long do we have until our luck runs out?


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