“The risk of a nuclear weapon being used is currently higher than at any time since the depths of the cold war,” said Izumi Nakamitsu, UN High Representative for Disarmament Affairs. “The war in Ukraine represents the most acute example of that risk.”

The Security Council met on the heels of President Vladimir Putin’s announcement last Sunday that it had reached an agreement with its neighbour, which has been any ally in Moscow’s invasion of Ukraine, to station non-strategic nuclear weapons inside Belarusian territory, which would be in place for aerial use, by July.

Dangerous rhetoric

Ms. Nakamitsu said the absence of dialogue and the erosion of the disarmament and arms control architecture, combined with dangerous rhetoric and veiled threats, are key drivers of this potentially existential risk posed by nuclear escalation.

“When it comes to issues related to nuclear weapons, all States must avoid taking any actions that could lead to escalation, mistake or miscalculation,” she said, recalling that all States parties to the Treaty on the Non-Proliferation of Nuclear Weapons, or the NPT – nuclear-armed States and non-nuclear weapon States alike – must strictly adhere to its commitments and obligations.

“They should return to dialogue to de-escalate tensions urgently and find ways to develop and implement transparency and confidence-building measures,” she said, appealing to States parties to the treaty to fully adhere to their obligations and to immediately engage in serious efforts to reduce nuclear risk.

‘Nuclear sharing’

The issue of “nuclear sharing”, the hosting by a non-nuclear weapon State of a nuclear-weapon State’s nuclear weapons, has existed for decades, across regions and under different arrangements pre-dating the Non-Proliferation Treaty, with the exception of the recent Russian announcement, she said.

“For the sake of all our security”, she echoed the UN Secretary-General’s call for Russia and the United States to return to full implementation of the New START Treaty and commence negotiations on its successor.

Russia: ‘A nuclear war cannot be won’

“We are pursuing cooperation with Belarus without violating obligations,” Russian ambassador and Permanent Representative, Vassily Nebenzia insisted. “We are not transferring nuclear weapons. We are talking about the retrofitting of airplanes and training teams in construction of a storage facility on the territory of Belarus.”

Russian tanks would not be in the Ukraine now, if the United States and its allies had not undertaken, what he described, as a coup d’état in Kyiv in 2014, “pumping the Kyiv regime with weapons”, he said.

Indeed, the US may have already deployed between 100 and 150 nuclear warheads in Europe, he said, recalling Moscow’s repeated calls on Washington to “set aside the cold war mentality” by returning US nuclear weapons to its own territory.

Russia must take “all requisite measures” in response to “provocative steps”, he said, given the fraying global security architecture, dictated exclusively by Washington, along with London’s recent decision to deploy armour-piercing ammunition to Ukraine.

“A nuclear war cannot be won”, he said.

United States: ‘Serious consequences’

Russia’s suggestion that this intended deployment is justified because of the use of armour-piercing ammunition supplied by Western forces, containing depleted uranium, is “ludicrous”, US ambassador Robert Wood said.

“Armour-piercing ammunition is in no way analogous to tactical nuclear weapons,” he said, adding that the Kremlin is attempting to limit and deter Ukraine’s efforts to defend itself, and manipulate matters to win the war.

Russia is seeking to escalate its brutal war rather than to seek peace, he said. Meanwhile, Belarus has recently enacted laws to enable the Russian deployment, he added.

Recalling a recent Russia-China security agreement, he said one provision stated that “nuclear-weapon States should refrain from deploying nuclear weapons abroad”.

“Any use of nuclear weapons in Ukraine would have severe consequences and would fundamentally change the nature of this war,” he said, calling on Russia to reconsider its decision about deploying tactical nuclear weapons inside Belarus.