Officials in Kyiv and several Western countries rejected claims made without evidence by the Kremlin that Ukraine is planning to use a “dirty bomb” — an explosive weapon designed to scatter radioactive material — on its own territory, characterizing them as an attempt by Russia to create a pretext for escalating the conflict.
“We all reject Russia’s transparently false allegations that Ukraine is preparing to use a dirty bomb on its own territory,” foreign ministers from the United States, France and the United Kingdom said in a Sunday joint statement, after Russian Defense Minister Sergei Shoigu made the unfounded claim in conversations with the countries’ defense ministers.
“The world would see through any attempt to use this allegation as a pretext for escalation,” the Western diplomats added.
According to summaries of Shoigu’s calls posted by the Russian Ministry of Defense, he told defense officials Sunday that he was concerned about “possible provocations by Ukraine with the use of a ‘dirty bomb,’ ” and noted that the situation in Ukraine is “rapidly deteriorating.”
Ukrainian officials immediately rejected Shoigu’s claims and accused Russia of making false threats to justify its own escalatory attack on Ukrainian territory. Dmytro Kuleba, Ukraine’s foreign minister, said he extended a formal invitation to U.N. nuclear inspectors to independently establish that Ukraine has “nothing to hide.”
The Washington Post could not verify either side’s claim. The Institute for the Study of War said that “the Kremlin is unlikely to be preparing an imminent false-flag dirty bomb attack.” Instead, the think tank noted, “Shoigu likely sought to slow or suspend Western military aid to Ukraine and possibly weaken the NATO alliance” with his allegations.
The incident has thrown Western and Ukrainian fears of a Russian nuclear attack into sharp relief, as the conflict hits the eight-month mark Monday, and frustrations grow within Russia that what officials initially conceived as a quick victory is turning into a protracted and costly conflict.
For many, it has also raised the question: What is a dirty bomb?
Dirty bombs are made of conventional explosives and radioactive material, designed to spread the material once they explode. They are not nuclear weapons and bear no resemblance to the atomic bombs used by the United States in Hiroshima and Nagasaki in 1945. Dirty bombs are far less powerful: Their “radiation could be dispersed within a few blocks or miles of the explosion,” according to the Massachusetts Department of Public Health.
As the department notes, the explosive substance in a dirty bomb is more likely to cause harm to humans than the radioactive material it carries. The goal of using a dirty bomb may not be maximal destruction, but rather an attempt to “create fear and panic, contaminate property, and require potentially costly cleanup,” it explains.
Shoigu’s claims that Ukraine would use a dirty bomb are particularly sensitive because Ukraine gave up its nuclear weapons in 1994 in return for a guarantee from Russia that it would not attack Ukraine.
Russia’s claims also come as analysts say the war in Ukraine has entered a new chapter — one that has seen Russia face several military losses, including Ukrainian gains in the south and the explosion that damaged the Crimean Bridge, which links Crimea to mainland Russia.
Moscow has retaliated forcefully, with massive strikes against Ukraine’s capital and its energy infrastructure ahead of winter. But Russian President Vladimir Putin is facing increasingly vocal criticism at home, as a growing number of war propagandists bemoan a perceived lack of progress and thousands of Russian men flee their country to avoid being forced to fight in Ukraine.
Against this backdrop, Putin has threatened to use “all means available” to defend Russian-occupied territory. “I want to remind you that our country also has various means of destruction … and when the territorial integrity of our country is threatened, to protect Russia and our people, we will certainly use all means at our disposal,” Putin said Sept. 21. “This is not a bluff.”
Shortly after that, Dmitry Medvedev, deputy chairman of Russia’s Security Council, wrote on Telegram that “Russia has the right to use nuclear weapons if necessary.” But he said Russia would do so only “in predetermined cases” laid out in its nuclear-policy documents.
CIA Director William J. Burns told CBS News last month that it was difficult to assess how serious Putin is about the potential use of nuclear weapons. He said the U.S. intelligence community has not seen “any practical evidence” that there is an “imminent threat.” Still, he said the United States should take the comments “very seriously.”
U.S. officials previously told The Washington Post that the United States for several months has been privately warning Russia’s leadership of the grave consequences that would follow the use of a nuclear weapon. Recent, more specific statements from Moscow appear to have set off alarm bells in Western countries and in Ukraine.
When asked about Putin’s nuclear threats, Col. Oleksandr Syrsky, commander of Ukraine’s ground forces, told ABC News in an interview released Monday, “We are and should be worried.”
Karen DeYoung, Paul Sonne and John Hudson contributed to this report.