WASHINGTON — In a series of calls with Western military leaders over the weekend, Russian Defense Minister Sergei Shoigu warned about a supposed Ukrainian “dirty bomb” and once more raised the prospects of nuclear escalation, despite the Kremlin's having been repeatedly warned against doing so by Western leaders.
On Monday, U.S. Joint Chiefs of Staff Chairman Mark Milley spoke with Gen. Valery Gerasimov, his Russian counterpart, about the dirty-bomb threat, a potential sign of concern in Washington over what the threat is intended to convey — and to whom.
The Russian Foreign Ministry’s short readout of Shoigu’s call with British Defense Secretary Ben Wallace similarly describes “concerns about a possible provocation by Ukraine with the use of a dirty bomb.” Shoigu made the same sort of warnings to officials in France and Turkey. He has also spoken twice to U.S. Defense Secretary Lloyd Austin since Friday.
Elaborating on Shoigu’s warnings, Russian authorities charged on Monday that Ukrainian President Volodymyr Zelensky’s government had reached out to the United Kingdom “regarding the possible reception of technologies to create nuclear weapons.”
In a post on Telegram, the social media network popular in Russia, Russian Lt. Gen. Igor Kirillov argued that “Ukraine has got a motive to use the ‘dirty bomb,’ as well as scientific, technical and production capacities to create it. Ukraine expects ‘dirty-bomb’ provocation to intimidate the population, increase the flow of refugees, and accuse the Russian Federation of nuclear terrorism.”
Western observers are skeptical — and mystified.
“It is long-standing Russian practice to accuse others of doing what it plans to do or has already done. I fear that Shoigu’s remarks are part of this pattern,” nuclear proliferation expert Paul Goble told Yahoo News. “But it is also part of a Russian effort to intimidate the West by threatening such things.”
It would make little sense for Ukraine to use a dirty bomb — conventional explosives laced with radioactive material — on its own territory, where its troops have been fending off Russia’s invasion. Striking within Russia would also fail to accomplish Ukraine’s defensive goals.
That left many observers wondering just what the Kremlin had in mind, and whether it was potentially using nuclear fears to distract from military setbacks. Ukrainian forces, fortified by Western weaponry, continue to retake ground lost to Russia during the first months of the invasion, which Russian President Vladimir Putin launched in February.
“Some are speculating that Russia may detonate a very low-yield tactical nuclear weapon and claim that the resulting radiation was caused by a Ukrainian dirty bomb,” physicist Edwin Lyman, who heads the nuclear safety program at the Union of Concerned Scientists, told Yahoo News.
“But it would be fairly easy to distinguish between even a very small nuclear weapon and a dirty bomb by the types of radiation that would result, as well as the consequences of the initial blast effect. So this doesn’t make a lot of sense to me,” Lyman added.
Russia has previously accused Ukraine of trying to create a nuclear disaster at Zaporizhzhia, the largest nuclear plant in Europe, and the only one in Ukraine that has been occupied by Russian troops. Then, as now, most observers were skeptical of Russia’s claims, while also worrying about what those claims may have revealed about the Kremlin’s plans.
In possession of the largest nuclear arsenal in the world, Russia has a number of terrifying options that could alter the trajectory of what was supposed to be a quick invasion of Ukraine culminating in the collapse of Zelensky’s government in Kyiv. Western support of Ukrainian resistance has turned the invasion into a debacle for Russian military leaders, for whom nuclear weapons could be an option of last resort.
Last month, Putin seemed to hint at Russia’s willingness to use nuclear weapons, leading President Biden to speculate that Russia was preparing for nuclear “Armageddon.” Some called Biden’s speculation irresponsible, but American visibility into Kremlin deliberations remains low, and high-ranking Russian officials seem willing to keep the possibility of nuclear escalation within the realm of the possible.
Zelensky sees Russian deception at work. “If Russia calls and says that Ukraine is allegedly preparing something, it means only one thing: that Russia has already prepared all of it,” he said in response to Shoigu’s calls.
In response to Shoigu, the governments of France, the United States and Great Britain issued a joint statement condemning his warnings.
“Our countries made clear that we all reject Russia’s transparently false allegations that Ukraine is preparing to use a dirty bomb on its own territory. The world would see through any attempt to use this allegation as a pretext for escalation. We further reject any pretext for escalation by Russia,” the statement said.
The three nations also reaffirmed their commitment to supporting Ukraine.
Shoigu’s calls were made after a prolonged period during which the Russian defense minister had been largely out of public view and was seen to be losing influence with Putin, who appears to be increasingly involved in military operations. Just why Shoigu was dispatched to contact his Western counterparts remains something of a mystery.
Ultimately, the risk of significant nuclear escalation remains low, according to experts. “The Kremlin is unlikely to be preparing an imminent false-flag dirty bomb attack. Shoigu’s claims further a longstanding Russian information campaign,” says an assessment from the Institute for the Study of War published on Sunday evening.
Shoigu’s threats are “likely intended to intimidate Western states into cutting or limiting support for Ukraine,” the ISW assessment suggests.
Last month a blistering Ukrainian counteroffensive saw Russian units forced into a disorganized retreat. Now the fighting is centered on Kherson, a strategically important city on the Dnipro River. There, too, Russia is facing setbacks.