What is a dirty bomb?
A dirty bomb is a conventional explosive device laced with another substance, for instance radioactive material, designed to contaminate the immediate surroundings of a blast area. In the case of a dirty bomb using nuclear material, no fission takes place (as would occur in the detonation of a nuclear weapon). Usually seen as a potential terrorist weapon, it would have limited utility in conventional warfare.
Why are we talking about dirty bombs?
Russia is alleging Ukraine plans to use a dirty bomb on its own soil and then blame it on Russia, a claim it is taking to the UN security council. The suggestion has been described as transparently false and absurd by senior western defence officials and Kyiv, the latter of which has invited UN nuclear inspectors to visit two sites named by Moscow as where a dirty bomb is being prepared.
Officials fear Russia is considering using a dirty bomb and then blaming it on Kyiv as a pretext for its own escalation, after a series of battlefield setbacks for Moscow.
So what is Russia up to?
In the first instance, Vladimir Putin’s aim appears to be to get the west talking about how a dirty bomb could be used and what that would mean, much in the same way that Moscow’s hints about using a tactical nuclear weapon in Ukraine dominated the news agenda.
Even if you think that it is more likely that Moscow would be behind such a move, it offers both the potential for a quick and dangerous escalation, and also the prospect of escalation being dangled to frighten the public and political leaders.
The Kremlin has a long history of using breaches of international norms – assassinations, invasions, war crimes in Syria – to gauge likely future responses by the west. Conversations about the potential use of nuclear weapons or what would happen in the event of the use of a dirty bomb could be a way of assessing red lines, as well as an attempt at nuclear blackmail aimed at countries supporting Kyiv.
Moscow has failed to prevent western countries sending modern weapons systems to Ukraine, but fear of its response has succeeded in making Washington and others hold back on longer-range weapons.
Why now?
Putin faces mounting challenges on all fronts. Russia’s exhausted troops are being pushed back in the south and east, not least around Kherson, where a battle for the city itself looks increasingly imminent.
Putin’s hope of using an energy crisis in Europe as a lever to turn public opinion against the war is also in trouble. Europe has been far more successful at filling gas storage for the winter than any had expected and the high wholesale price for gas – of which Russia was a beneficiary – is dropping rapidly.
The war has led Nato and European countries to call Moscow’s bluff on a wider escalation beyond Ukraine’s boundaries, leaving a dwindling threat now largely occupied by talk of nuclear escalation.
A number of observers believe that Russia’s key aim at present is to freeze the lines of the conflict and push Ukraine into negotiations – rejected by Kyiv, which has stated its objective of liberating all Russian occupied areas.
Should we be worried about an escalation?
Ned Price, a US state department spokesman, reiterated on Monday: “We’ve not seen any reason to adjust our own nuclear posture, nor do we have indications that Russia is preparing to use nuclear weapons. But we’ve heard these very concerning statements, and we wanted to send a very clear signal [to Moscow].”
Whether Russia is capable of escalating further conventionally is also open to question. Moscow has already upped the tempo of missile and kamikaze drone strikes on civilian infrastructure, including that related to energy supply as winter approaches, and the large partial mobilisation of 300,000 troops has created more problems than it has solved, funnelling barely trained and ill-equipped soldiers to the frontline. A new regional military pact with Belarus alongside Russian troop deployments there, also appears to be largely sabre-rattling.
While the Russian claims about a dirty bomb – and what they may mean – have clearly spooked western officials, the flipside is the unusual flurry of high-level contacts between Russian and western officials. It is clear these have been used on the western side to reinforce messages about red lines regarding nuclear weapons use and unconventional weapons like dirty bombs, but it is just possible that those contacts may be the point of all this.
So is this all a scare tactic?
Possibly. Observers have pointed out that the Russian story about the origins of a potential dirty bomb is not convincing and that Moscow has previously warned of impending chemical and biological attacks that (thankfully) have failed to materialise. “This is not the first time Russia alleged there will be some kind of false flag WMD use in Ukraine,” wrote Andrei Baklitskiy of the UN Institute for Disarmament Research. Russia has warned about Ukraine preparing nuclear and chemical attacks since April. Given Russia’s desire to freeze the conflict and the flurry of diplomatic activity, including an appeal to hold talks in the UN security council, it is possible Russia is looking for any pretext to hold talks while it reinforces its position on the battlefield.
