Let’s say hard evidence emerges that Russia was in fact responsible for the suspected attack on Sergei Skripal, the former Russian military intelligence officer who spied for MI6, and his daughter Yulia in Salisbury. Comparisons have inevitably been drawn with Alexander Litvinenko, the Russian dissident and former intelligence officer poisoned by a dose of radioactive polonium-210 in London – an operation British intelligence quickly became convinced had been planned in the Kremlin.

In 2010, Skripal was swapped in an exchange for 10 Russian spies being held in the US. But Russian intelligence officers can be unforgiving. And if they were responsible for the attack on Skripal, they could well have had a nod and a wink from Putin himself. A public inquiry into Litvinenko’s murder concluded in 2016, a full 10 years after the event, that there was a “strong probability” that the Russian security service the FSB was responsible for Litvinenko’s fatal poisoning, and that Putin “probably” approved it. The Russian ambassador was summoned to the Foreign Office, and the assets of the two main suspects, Andrei Lugovoi and Dmitry Kovtun, were frozen. Litvinenko’s widow, Marina, chided the British government for not doing more.

Play Video 2:03 Who is the Salisbury spy Sergei Skripal? – video explainer

The former head of MI6 said 'Engaging with the Russians was not being nice with them, but being tough'

What could the British government do now if there was evidence that Moscow was involved in the attack on Skripal, short of indulging in hand-wringing rhetoric? Economic sanctions have already been imposed in response to Putin’s military incursions into Ukraine. A number of Russian individuals and Putin’s cronies may have been hit by them, but Putin has not been.

Perhaps the government could break off diplomatic relations, indulge in a tit-for-tat expulsion of spies. But this would risk playing into Putin’s hands. He has cultivated the Russian view that the west has sought to humiliate Russia ever since the fall of the Soviet Union. It is not surprising that he revels in trying to humiliate the west in return. And for Putin, a Britain – preoccupied and divided by Brexit, with its diplomatic, economic, and military clout eroding – is a prime target. This does not mean that he was involved in any way with the awful attack on Skripal; just that if there was any suggestion that he was, he would ignore any British protests, even mock them – especially now, as he looks forward to being re-elected Russian president later this month.

British army chiefs, enthusiastically cheered on by the defence secretary, Gavin Williamson, have been upping the ante, warning of the growing threat Russia poses. Russia could cause “thousands and thousands and thousands” of deaths in Britain by crippling the country’s infrastructure and energy supply, Williamson told the Telegraph in January. Moscow quickly dismissed the warnings as “something out of Monty Python”. Shortly before, Stuart Peach, chief of the defence staff, warned that there was a growing risk of a Russian attack on undersea communications cables, posing a potentially “catastrophic threat” to the internet and international trade.

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This all sounds like a crude pitch for more money for the defence budget. Both John Sawers, head of MI6 until 2014, and Robert Hannigan, former director of GCHQ, pointedly declined to comment on Williamson’s warnings when invited to, when they gave evidence to parliament’s national security strategy committee in January. Sawers also revealed that when he was head of MI6 he was banned by ministers from talking to his “Russian counterparts”. Engaging with the Russians was not being nice with them, he said, but being tough.

Adam Thomson, a former permanent representative to Nato, told the committee that he was concerned about all the rhetoric aimed at Moscow. “We need to engage with Russia,” he said. Mark Sedwill, the government’s national security adviser, in a little-noticed address last summer, urged his audience of senior army officers to see things from Moscow’s perspective. When the west talks about containing Russia, the Russians see it as “encirclement”, he said.

These interventions by senior security figures are telling. They reflect the frustration about the inability of the west – Britain in particular – to influence the Kremlin. Would engaging with Putin stop any future attempt to kill former Russian spies in Britain? Perhaps not. But the British government should calm down and encourage British intelligence officers to start engaging with their Russian opposite numbers. After all, such official meetings took place throughout the cold war. It could make Putin’s Moscow and its professional spies take Britain more seriously.

• Richard Norton-Taylor writes for the Guardian on defence and security

• This article was amended on 7 March 2018. The Russian presidential election is this month, not next month as an editing mistake led an earlier version to say. In addition, Adam Thomson was a permanent representative, not secretary, to Nato.