"This being the nuclear age, it is the paramount rule of international politics that a great nuclear power should not put another great nuclear power in a position where it must choose between suicide and surrender."
So wrote Walter Lippmann, the great US journalist, in 1961. Lippmann understood the nuclear age better than most. He knew it was about much more than the number or type of warheads a nation possessed. It was a three-dimensional game of chess, in which psychology and, crucially, balance and predictability were as important as the nukes themselves.
Among Lippmann's other credits was being the first mainstream commentator to give currency to the phrase and concept of "Cold War".
Few born since the Soviet Empire collapsed in 1989 have had reason to contemplate the machinations of nuclear deterrence. It's not that we no longer possess the means to vaporise with nuclear explosions everyone on the planet several times over – we very much do – but that the clash of great powers was thought to be over; the "end of history" reached.
"It has been assumed that [countries] won't be used because the horror of it is too great," Dr Patricia Lewis, head of the international security programme at the Chatham House think tank, told The Telegraph.
Since the end of the Cold War, the number of nuclear weapons across the globe has dropped drastically, from a peak of around 70,300 in 1986, to roughly 12,700 in early-2022. But there are still more than enough. Russia and the US have by far the largest arsenals, with 5600 and 6200 weapons, respectively.
These weapons are much more powerful than those dropped on Japan. Just 50 modern bombs could kill 200 million people – or the combined populations of Britain, Canada, Australia, New Zealand and Germany, it is estimated.
President Vladimir Putin, of course, grew up a warrior of the Cold War and some analysts believe that he – and many in the security apparatus that surrounds and sustains him – never really left it behind.
They were deeply humiliated as KGB operatives and soldiers when the Soviet Union collapsed, and have become increasingly angry and resentful over what they see as the West's triumphalism in the three decades since.
When Putin called his commanders to the Kremlin on Sunday to order them to place Russia's deterrent under a "special combat service regime", it was unmistakably a paranoiac creature of the Cold War who was doing the talking.
Not only was his language bellicose and wrapped in the tortured syntax of deterrents, he was sitting at the end of table a good 20 feet from his Defence Minister and the Chief of the General Staff of the Russian armed forces.
"Putin's standard procedure now is to inject nuclear weapons into non-nuclear crises," said Adam Mount, director of the Defence Posture Project at the Federation of American Scientists, in a thread on Twitter.
"Putin wants to transform every crisis into nuclear crises to generate leverage by shifting a competition from an area where he's relatively weak (economics, the streets of Kyiv) to one where he's relatively stronger (nuclear weapons). We don't have to acquiesce."
1/n. The bottom line: there is a wide range of steps that Russia could take under a "special combat service regime" for its deterrence forces.
— Adam Mount (@ajmount) February 27, 2022
Western intelligence agencies are watching closely to see exactly what Putin's order means in practice, but most have interpreted it as a shift to a general state of nuclear readiness. The US could match the Russian move and raise its own response to Defcon 3 – "known to moviegoers as that moment when the US Air Force rolls out bombers, and nuclear silos and submarines are put on high alert", as The New York Times puts it – but has so far chosen not to.
Experts suggested there were two reasons that the US and other nuclear-armed Nato nations, including the UK and France, are not following suit.
"The United States won't want to alert because then it would certainly be a nuclear crisis," said Dr Mount. "The dominant strategy is to do what we can to impose costs in the areas where Putin is weak rather than agreeing to compete where Putin is stronger."
There is also, in practical terms, little to be gained as Nato is, as a matter of course, always ready to strike back.
"The day-to-day posture of US forces is capable of retaliating for a Russian first strike attempt regardless of the alert levels of Russian strategic forces," Mount added. "Bombers at US bases would become more vulnerable without alerting, but US submarines and ICBMs (which have more than 75 per cent of US warheads and more than 90 per cent of launchers) would be fully capable of retaliating for a hypothetical attack on US bomber bases. So no action is needed for stability."
Underpinning the nuclear standoff which has existed between Nato and Russia for decades is the doctrine of Mutual Assured Destruction (MAD). It saw us through the Cold War, but experts caution it may not be as reliable today. And even in the Cold War there were mistakes that brought nuclear armageddon close.
In October 1962, at the height of the Cuban Missile Crisis, a Russian commander operating in a sweltering submarine with broken air-conditioning almost launched a tactical nuclear torpedo. The Soviet B-59 sub was under fire from US forces, who were dropping non-lethal depth charges. The officer was unaware the action was designed to make him surface, and instead interpreted the situation as the beginning of a third world war.
But launching the torpedo required the approval of all three senior officers on board and one – Vasili Alexandrovich Arkhipov – refused. He was honoured with the "Future of Life" award in 2017, almost two decades after his death, for averting a nuclear conflict.
A simple mistake or misunderstanding remains one of the principal risks today – a risk that is increased because, over the past 30 years, nuclear drills have been practised less frequently and the technology has aged.
"One risk of increasing the alert level is that it could require officers to perform tasks that they may or may not have practised previously," Mount said. "That could increase the risk of an accident, which varies depending on exactly which steps Putin has ordered."
Another risk – one that threatens the deterrence provided by MAD – is the proliferation of smaller "battlefield" nuclear weapons.
"Russian nuclear forces can be divided into strategic (which can reach the US) and nonstrategic (which can't)," said James Acton, co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace. He added that it is not yet clear whether Putin's order would result in both being "alerted" or readied for action.
Given that Nato's systems for strategic retaliation are already in place (our Trident submarines are already at sea), it would be intelligence which suggests Putin is preparing tactical nukes that would cause most immediate concern.
"Day to day, Russian nonstrategic warheads are kept separate from delivery systems in 'centralised' storage (an organisational not a geographic term)," Dr Acton said. "A first step to prepare these warheads for use would be to move them to the sites where the delivery systems are located."
"Mating non-strategic weapons [with] warheads… would be crazy escalatory and would probably set alarm bells ringing across Europe, both for what it could portend for Ukraine on top of the implications for the rest of the continent," added Mike Black, a former US Air Force munitions officer.
Others fear most about Putin himself and his state of mind. Are we, as Lippmann worried in 1961, about to push someone with their finger on the nuclear button to choose between suicide and surrender?
"The people who know Putin the best – people I know in Russia – are worried about his recent nuclear statement. The people who know him the least are saying it's cheap talk," warned Professor Michael McFaul, an American academic and diplomat who served as the US Ambassador to Russia from 2012 to 2014, on Sunday.
Sahil Shah, a policy fellow at the European Leadership Network who advises senior US and European decision makers on reducing strategic and nuclear risks, said that not everything rests on Putin. There are checks and balances in place in Russia, just as there are in the West.
"Russia has inherited a two-person rule throughout the chain of nuclear command and control from the Soviet days," he told the Telegraph. Three people have "nuclear footballs", or codes needed to authorise the launch of weapons: the President, Minister of Defence and the Chief of the General Staff. It is thought that two of the three codes are needed to grant the military permission to deploy nuclear weapons.
"In effect, the Minister of Defence or possibly the Chief of the General Staff would need to validate the authorisation to use nuclear weapons for the Russian military to launch them," Shah said. "If that were to occur, the order would be passed to the Nuclear Strategic Forces Command and Control Centre, where two officers would need to simultaneously carry them out."
A final area of thought nuclear strategists are turning their attention to are what the American's call "off-ramps" – concessions that can be offered which would allow Putin to back off while saving face.
In the Cuban Missile Crisis, for example, President John Kennedy saved Premier Nikita Khrushchev's blushes (to some extent) by agreeing to remove Nato missiles from Turkey in return for the Soviets dropping their attempts to arm Cuba.
"It's difficult for the West to create a de-escalation pathway; much presumably depends on how Putin views the domestic consequences of his backing down – something over which the West has no control," Dr Acton said.
"But we can at least reduce the costs to his backing down by making it clear that the most punishing sanctions – central bank and Swift – will be lifted if the status quo ante is restored.
"I encourage others to think creatively now about other elements of a potential off-ramp for Russia. To be sure, it's unsavoury to think about providing inducements to Putin for backing down while Ukrainians are being slaughtered.
"However, Ukraine and Russia are now reportedly engaged in negotiations. We can strengthen Ukraine's hand in negotiations by making the consequences of a deal more attractive for Russia."
Iranian missiles hit Tel Aviv, Haifa, and Ness Ziona on Sunday morning.