Mr Putin is playing by new rules. He’s ready for a fight – but are we?

The attempted murder in Salisbury shows Russia wants to sow chaos: call it the Gerasimov doctrine

Just over five years ago, the head of the Russian armed forces, General Valery Gerasimov, gave a speech in the Kremlin about the future of warfare. You don’t need guns and tanks to defeat an enemy, he said: there are, nowadays, more effective ways of winning. Computer hacking, TV propaganda, criminal skullduggery – all can unnerve an opponent and weaken alliances. This became known as the Gerasimov doctrine, and its latest victims are lying in a Salisbury hospital. Not so much a declaration of war, but a reminder of one already under way.

This is what Theresa May has been trying to get across at the Brussels summit. She wants other European countries not to repeat her mistake. As Home Secretary, she acted too slowly when Alexander Litvinenko was found to have been poisoned by EX-KGB officers. She was reluctant to recognise the implications: no one, then, wanted to think that they might be engaged in a new kind of conflict with Russia. No one wants to believe that now, but the Salisbury poisoning has focused British minds. Now, Mrs May wants to focus some European ones.

Since Sergei Skripal and his daughter were poisoned, British officials have been generous with the information they have shared with their allies. Raw data from the blood tests have been sent abroad so France, Germany and the United States could see why Porton Down scientists are confident that Novichok, a nerve agent, was used.

There are four known strains of Novichok, and the one found in Salisbury, A234, could be made in only a small number of countries skilled in biological weapons. Of the potentially hostile ones – Iran, North Korea, Russia and China – who would have an incentive to frame Russia? There would be no motive, or logic.

The Russian mafia might conceivably have acquired the Novichok. But to deliver a chemical weapon requires expertise that only a government would possess. To touch or sniff Novichok is fatal; to smear some on a glass (or a car door handle) would pose a lethal risk to the assassin. The mob would not go to such lengths. When they want someone dead they make it look like an accident, or suicide. Gangsters hate publicity. To use nerve agent is to start an international event.

This is why so many countries have been persuaded that Russia was behind the attack. There are other possibilities, but none credible.

Vladimir Putin has form when it comes to assassinating enemies, and he was known to have been operating an undeclared chemical weapons facility. The attempted murder in Salisbury fits entirely with the tactics Gerasimov described: “Blurring the lines between war and peace.” A hit here, a computer hack there – aimed at destabilising and discombobulating adversaries.

The Kremlin’s test, this time, would be to see how Britain would respond. And to see how many of our allies could be persuaded to join in.

The response this time was swift, robust and synchronised because Russia has been using these tactics against several European nations. Swedish defences are constantly tested by Russian aircraft. Estonia has come under Russian cyber-attack and Emmanuel Macron has already been the victim of Russian propaganda.

The Kremlin’s aim is not to back Marine Le Pen, or anyone else. Its aim is make its enemies look stupid, or make them suspicious of each other – perhaps by leaking conversations. And to create just enough doubt to stop an alliance – like the European Union – from speaking with one voice.

British officials have already been abroad proposing a joint plan of response. The feeling is that it was a mistake, after Litvinenko’s murder, to wait for independent verification that he had been killed by polonium. That takes time – and in that time, Russia plants doubt. Its state media outlets have so far come up with about 30 rival theories about how Mr Skripal could have been attacked. So if the Kremlin wants delay, it’s time to speak quickly. If it wants division, there must be a show of unity. These are the new rules.

Mrs May is, of course, unlikely to get a strong response from the EU. It struggles with foreign policy because any one of its 28 members can use its veto (a statement blaming the Kremlin for the Salisbury attack, for example, was watered down by Greece). “Russian money is everywhere,” one Cabinet member tells me. “In Bulgaria, Romania, Cyprus – influence is easy to buy.”

This helps Mrs May make another point: that after Brexit, European countries must find a new way to work together.

It’s often said that Putin, a former KGB officer who obsesses about Nato, is stuck in a Cold War mindset. But he now excels in 21st-century tactics; it’s the West that is stuck in the Eighties. We look at the Skripal case in bafflement, wondering why on earth Putin would renege on a spy swap deal – something that was never done in the Soviet era. But the Cold War was about rules, protocols and procedure. The new Moscow rules are about chaos, lies and unpredictability. If your opponent can only deal with certainty, then you’ve got him. Send unmarked troops into Crimea and it’s yours.

While Mrs May is asking her European counterparts for a concerted response, she should hope they don’t ask too many questions about hers. She acted quickly over Skripal, expelling 23 Russian spies – in response, the Kremlin expelled 23 lower-ranking Brits from Moscow.

But this is a long-term campaign, not just a diplomatic tit-for-tat. The thinking inside Government is to call upon three resources: cyber warfare, a large standing army to deter antagonists and finally the BBC World Service – seen as a powerful weapon in the information wars.

The flaw here is rather obvious. The army is shrunken and cash-starved, and the BBC World Service has been closing stations after years of cuts. Mrs May is quite right to ask European allies to get serious about the Russian menace, but there’s plenty to do at home. The word from her government is that Russia has “shown itself to be a strategic enemy, not a strategic partner”. A new conflict, with new rules – and one for which Putin is fully equipped. The question is: are we?