Western officials are engaged in “prudent planning” behind the scenes to prevent chaos and panic in their home countries in the event Russia was to detonate a nuclear bomb in or near Ukraine. Although a nuclear crisis is considered highly unlikely, the insider said officials internationally were re-examining plans to provide emergency support and reassurance to populations fearful of nuclear escalation. Hints of the thinking emerged in a briefing by an official on Friday, who was asked if there would be measures in place to prevent panic buying or people fleeing cities en masse in fear of escalation after a nuclear event. Governments were engaged in “prudent planning for a range of possible scenarios” said the western official, who was speaking on condition of anonymity, although they stressed that any use of nuclear weapons by Russia in the war would be abhorrent. Public information campaigns and even school drills on how to survive a nuclear war were a feature of the cold war, including the duck and cover campaign in the US in the 1950s, Protect and Survive from the UK in the late 1970s and “Everyone has a chance” in West Germany in the early 1960s. These campaigns were the subject of considerable criticism and parody for their suggestion that it could be possible to survive an all-out nuclear conflict, although in this case the focus is supposed to be on preventing public panic over fear of an uncontrolled nuclear escalation that would lead to major cities being targeted. Kate Hudson, the general secretary of the Campaign for Nuclear Disarmament, said: “This ‘prudent planning’ harks back to the British government’s cold war-era Protect and Survive campaign – which was roundly condemned by CND as giving the false impression that a nuclear attack could be survived by whitewashing windows and other irrelevances.” As Moscow has suffered reverses on the battlefield in Ukraine since September, Vladimir Putin has ratcheted up the nuclear rhetoric, saying last month that he would use “all available means” to defend Russian territory. The western official said the Russian president’s comments about nuclear use were “deeply irresponsible” and no other country was talking about nuclear weapons. “We do not see this as a nuclear crisis,” they said. Echoing comments made by the US, the official said: “Any use of nuclear weapons would break a taboo that has held since 1945” which would “lead to severe consequences for Russia, as well as for everybody else”. Towards the end of last month, Jake Sullivan, the US national security adviser, said there would be “catastrophic consequences” for Moscow if it sought to deploy a tactical nuclear weapon, which can have the power of six or seven Hiroshima blasts. The west does not want to spell out how it might respond, to preserve a deliberate ambiguity – and on Friday the official would not be drawn on what nuclear armed countries might do. But the expectation is that to avoid rapid escalation any initial response would be non-nuclear. On Thursday, Emmanuel Macron broke ranks and said he would not order a like-for-like retaliation if there was a Russian nuclear strike in Ukraine. The French president said the country’s fundamental interests “wouldn’t be directly affected at all if, for example, there was a ballistic nuclear attack in Ukraine, in the region”. Earlier this week, Jeremy Fleming, the head of the GCHQ spy agency, said he not seen any sign that Russia was preparing to use a tactical nuclear weapon in or around Ukraine. It is his agency’s job to help monitor Russian military movements, and whether its military was trying to pair a nuclear warhead with a conventional missile. Experts generally believe that Putin is engaged in a bluff, trying to provoke fear and uncertainty in the west, to ensure that the US or Nato does not enter the war on Ukraine’s side.