

It will be interesting to see how or if the former prime minister will choose to use this special relationship, especially with President Zelenskyy, going forwards. However, Mr Johnson made clear there would have to be a western response, noting in his interview with Sky News's Mark Austin that there "are all sorts of options".Ī decision by the UK to send anti-tank weapons to Ukraine, the first of any European nation, in the run-up to the war - followed by a steady flow of increasingly lethal munitions - has made Mr Johnson a legendary figure amongst the Ukrainian public and leadership.

NATO allies have a deliberate policy of "strategic ambiguity" when it comes to anything nuclear - refusing to set out in public how they might retaliate should the Kremlin chose to break the nuclear taboo and use an atomic weapon against Ukraine. Having been the leader of a nuclear power, Mr Johnson would have been carefully briefed by officials about the risk of nuclear escalation by Russia and how western allies, led by the United States, might respond. It also gave Mr Johnson privileged access during his time in office to the private thoughts of Mr Zelenskyy, as well as a deep understanding of Ukraine's need to defeat Russia’s invasion and the threats it could face - all the way up to Vladimir Putin launching a nuclear strike.

His uniquely close relationship with Ukrainian President Volodymyr Zelenskyy and his decision to be a leading voice amongst western allies in supporting Ukraine from the outset of the invasion has made London one of Kyiv’s most trusted and valued partners. He may be a former British prime minister, but any comment made by Boris Johnson on the war in Ukraine still carries weight, especially when it comes to nuclear weapons. By Deborah Haynes, security and defence editor
