Russian President Vladimir Putin has stated Russia will store nuclear weapons in Belarus on March 25 in response to the UK announcement it will send depleted uranium shells to Ukraine.

“We have already helped the Belarusians re-equipped aircraft, 10 types of aircraft are ready for the use of tactical weapons, we handed over the Iskander, [and] from April 3 we will start training crews, we will start building a storage facility for nuclear weapons,” Putin said in televised remarks.

Putin said the missiles would only be “stored” in Belarus and would remain under the full control of the Russian army. Belarus President Alexander Lukashenko has long wanted to house some Russian nuclear weapons in his country as a deterrent to his perceived military threat from the West.

“On July 1, we are finishing the construction of a storage facility for tactical nuclear weapons in Belarus. Moscow and Minsk agreed that, without violating the obligations under the START Treaty, they will deploy tactical weapons in Belarus. We are not transferring our tactical nuclear weapons to Belarus, but we will deploy them and train the military, like the United States in Europe,” Putin added.

Exiled Belarusian opposition leader Svetlana Tikhanovskaya said that Russia's deployment of tactical nuclear weapons "grossly contradicts the will of the Belarusian people", the BBC reported.

The move comes as the latest escalation in Putin’s nuclear weapons threats against the West as part of his war in Ukraine. Moscow has already made ten Belarusian bombers nuclear weapons-ready, although no nuclear weapons have been transferred yet.

Moscow bitterly objected to the UK’s announcement last week that it was sending depleted uranium shells to Kyiv, which it claimed was a transfer of weapons “with nuclear components”, and as such is now responding in kind.

Depleted uranium is made from the stable isotopes of uranium left over from enriching the ore to get the 235 isotope that is used in nuclear reactors. While the other isotopes are mildly radioactive, their half-lives are so long that they are not considered to be unduly dangerous. And as depleted uranium is much denser than lead it is valued for use as armour and armour-piercing shells.

The use of depleted uranium materiel remains very controversial but was used by Western forces in both the war in the former Yugoslavia and the Iraq war.

Putin said the missile deployment to Belarus was in response to a long-standing request by Lukashenko, who has allowed Russia to use the country as a launch pad for attacks on Ukraine. Putin already put Russia’s nuclear forces on “special alert” in February.

Putin said the work on building storage units for tactical nuclear weapons in Belarus will be complete by July 1. After the Cold War the US reduced its arsenal of tactical nuclear weapons to 230, whereas Russia has maintained a stock of some 2,000 tactical missiles, the Financial Times reports. Typically the smallest US nuclear devices have a blast force of five megatonnes, whereas Russian tactical nuclear missiles have a blast force of as little as one megatonne, enough to destroy central Kyiv, but that would leave most of the suburbs intact, albeit damaged.

A recent poll found 89% of Ukrainians would be prepared to continue the fight against Russia even if Putin used a tactical nuclear weapon against the country.

Spring offensive.

The escalation of nuclear tension comes at a time when it has been widely reported that Ukraine is preparing for a spring offensive that might include an attack on Crimea, which Moscow has long considered Russian sovereign territory.

Any Ukrainian attempt to capture Crimea could be met with a nuclear response by Moscow, former Russian President Dmitry Medvedev warned on March 24. He insisted, however, that Kyiv’s claims that it could seize the peninsula are nothing more than hollow threats.

Medvedev, who currently serves as the deputy head of Russia’s Security Council, added: “if we talk about some sort of serious offensive that is associated with an attempt to retake Crimea, it is quite obvious that this is the basis for the use of all means of protection, including those provided for by the fundamentals of the Doctrine of Nuclear Deterrence, when the use of any types of weapons against Russia threatens the existence of the state itself.” Medvedev stressed that any attempt to break off part of Russia would be considered as a threat to the nation’s existence, which according to Russia’s nuclear doctrine justifies the use of nuclear weapons.

“Therefore, draw your own conclusions. There are absolutely grounds for using any weapon here. Absolutely any kind. And I hope our ‘friends’ across the ocean understand this,” the former president said.

He also stressed that the prospect of a nuclear conflict has not faded, but instead continues to grow. Every day that Western weapons are delivered to Ukraine, the closer the world moves towards a “nuclear apocalypse,” Medvedev cautioned, adding that “it doesn’t mean that this will happen, but the horsemen of the apocalypse continue to move.” Just how seriously to take Putin’s implicit nuclear weapons threat has caused a lot of debate, however; while the possibility exists, more sober Russia watchers believe Putin won’t go that far. The Financial Times reported that Putin considered using a tactical nuclear strike against Ukraine last autumn, but on balance decided against it, as it wouldn’t bring about sufficient battlefield advantage.

As Michael McFaul, the former US ambassador to Russia, said in an opinion piece in bne IntelliNews, the main problem with a nuclear strike against Ukraine is that it would almost certainly provoke a major escalation in the West’s military support for Ukraine, including the provision of offensive weapons that the West has so far been very reluctant to supply. It could also lead to the direct involvement in the war of Nato troops on the Ukrainian battlefields. As bne IntelliNews has argued, so far, the Western policy has been to provide Ukraine with enough weapons so that it doesn’t lose the war with Russia, but not enough so that it can win.

Cold War missile treaties.

Putin's decision to move nuclear missiles to Belarus is the latest step in the slow escalation of tensions after the Cold War missile security infrastructure was largely dismantled since the end of the Cold War.

The last serious nuclear deployment by Russia was the decision to move its nuclear-capable Iskander missile system to the Kaliningrad enclave in 2016 that rattled the Baltic states and Poland.

The process started in 2002 when under former president George W Bush, the US unilaterally withdrew from the Anti-Ballistic Missile Treaty (ABM treaty), a key piece of Cold War security infrastructure, despite Moscow’s stringent objections. That was followed by Washington's decision to withdraw from a number of other treaties, including the Intermediate-Range Nuclear Forces Treaty (INS Treaty) in 2019 under former president Donald Trump and the Open Skies Treaty in 2020.

At the same time, Nato launched a “missile shield” concept in 2002, with defence surface-to-air missiles deployed in Poland and Romania a decade later. The shield was nominally set up to protect Europe from attacks by rogue states like North Korea and Iraq, but with the missiles deployed facing Russia’s European borders, the Kremlin saw the missiles as targeting Moscow. At the same time Nato began expanding eastwards in 1999, when Poland, Hungary and Czechia joined, eventually adding eight new members.

Putin has long objected to the expansion of Nato, most famously in a speech at the Munich Security Conference in 2007, when he warned that Russia would “push back” if the expansion continued. Putin cites the threat to Russia that the Nato expansion represents as one of the justifications for starting his war in Ukraine.

Following Munich, Russia called for a new inclusive pan-European security deal to replace the Cold War-era Nato security arrangements, which specifically excluded Russia, although Russia maintained diplomatic relations with the military alliance.

In 2008 the newly elected president Dmitry Medvedev travelled to Brussels on his first foreign trip bearing a detailed blueprint for a new security deal, but it was rejected out of hand. Frustrated at the lack of progress, and feeling its security concerns were being ignored by the West, relations deteriorated rapidly after Russian Foreign Minister Sergei Lavrov gave his “new rules of the game” speech in February 2020, threatening to break off diplomatic relations with the West if it continued its dual policy of doing business with Russia with one hand and applying sanctions with the other. Diplomatic ties with Nato were broken off in October 2021 as Russia started to mass its forces on Ukraine’s border.

New START.

There was one last chance to reverse the growing tensions, as following his election in 2020, US President Joe Biden began to reverse the long-standing US policy of dismantling the Cold War missile security infrastructure. As a Senator in 2002, he had objected to the US withdrawal from the ABM treaty (Anti-Ballistic Missile Treaty), arguing it would destabilise relations with Russia. During his first week in office, Biden signed off on renewing the START missile treaty in January 2021.

The Kremlin jumped at the prospect of putting back in place the Cold War-era security infrastructure and immediately proposed starting talks to renew the INS Treaty as well. However, those talks never began as, thanks to the Kremlin’s new hard line on Ukraine’s status, tensions rose throughout the year until in December the Russian Ministry of Foreign Affairs issued an eight-point list of demands, headed by a “legally binding” guarantee that Ukraine would never join Nato.

Putin suspended the new START treaty in February this year, although he didn’t go as far as withdrawing from it completely, leaving the door open for a possible resumption of arms control talks in the future. In the same month Putin revoked the 2012 foreign policy law, changing its focus from dealing in a “co-operative” way with foreign powers based on “respect for neighbouring countries’ sovereignty” to a new more aggressive approach based on “establishing external conditions that favour Russia’s long-term development”.

The placement of nuclear weapons in Belarus marks a new chapter in what is slowly turning into a new arms race. In parallel with Russia’s diplomatic efforts to rebuild the Cold War-era security infrastructure, Putin began to invest heavily into the modernisation of the army in 2012 and construct a Fiscal Fortress that has sanction-proofed the Russian economy. In particular, the Kremlin has invested massively into the development of its new hypersonic missiles which Putin showcased during his 2018 state of the nation speech. Russia claims that these missiles can penetrate all the US missile defence systems and Russia is currently ahead in this technology. The US Navy announced last week that it was investing $3.6bn over the next five years to build 64 similar missiles, as it tries to catch up.

Despite the threat of a renewed arms race, the Kremlin remains a stickler for its remaining commitments to security agreements, as despite its aggressive sabre rattling, the Kremlin has an eye on possible future security talks, should the war in Ukraine end and diplomacy resume.

Putin highlighted in his Belarus nuclear missile transfer announcement that Russia will not violate its commitments to its nuclear non-proliferation obligations. As part of his justification for the move, he highlighted that the US has the same commitments to non-proliferation, yet has placed nuclear missiles in at least six partner countries.

“There is nothing unusual here: first of all, the US has been doing this for decades,” Putin said. “They placed their tactical nuclear weapons in six different allied Nato countries in Europe… we have agreed to do the same thing, without, I stress, violating our international non-proliferation obligations,” he added. “They have [tactical nuclear weapons] in certain countries, prepare the delivery systems and train the crews. We’re planning to do the same thing.” So far the US has taken the announcement calmly. US National Security Council spokeswoman Adrienne Watson said the US has not seen any signs Russia is moving towards using a nuclear weapon.

"We have seen reports of Russia's announcement and will continue to monitor this situation. We have not seen any reason to adjust our own strategic nuclear posture nor any indications Russia is preparing to use a nuclear weapon. We remain committed to the collective defence of the Nato alliance," the statement says. In turn, the White House issued a similar written statement.