Relations between the west and Russia have deteriorated sharply amid concerns about a US-led military strike in the Middle East, prompting the United Nations secretary general to declare “the cold war is back with a vengeance”.

Adding to tensions on an extraordinary day of tit-for-tat exchanges, the UK published previously classified intelligence making fresh claims about the nerve agent attack in Salisbury, including that Russia had tested whether nerve agents could be applied to door handles.

Q&A What are the military options in Syria? Show Hide In theory there are three alternative responses - the first a punitive strike such as the US attack on the Shayrat air base in April 2017 that saw 59 Tomahawk cruise missiles hit the the air base in response to a chemical weapons attack. The second level of attack is to seek to prevent Syria attempting to use chemical weapons again by destroying the relevant facilities, the means of delivery and imposing a punishment. The third level of activity is to seek to weaken the entire Assad military infrastructure or even attack Assad's presidential palace, as well as Syrian military headquarters. But there is no appetite in Western capitals to forcibly dislodge Assad from office, even if there may be an unspoken wish to change the way the Syrian government negotiates at UN peace talks in Geneva.



Military planners in the US, Britain and France, awaiting a final decision from their respective governments, are preparing plans for airstrikes in Syria in retaliation for an alleged chemical weapons attack by the Russian-backed president, Bashar al-Assad. Although anxious to avoid hitting Russian planes and military personnel based in Syria, the danger is of miscalculation and Russian retaliation.

António Guterres, seemingly alarmed by the speed of events, told an emergency meeting of the UN security council that the current volatility could have profound ramifications in the Middle East and beyond.

The UN secretary general suggested the danger was even greater than during the cold war because the safeguards that existed then to manage such a crisis “no longer seem to be present”. He added that there was no military solution to the Syrian conflict.

On a day of rapid developments that underscored the rationale behind Guterres’ comments:

Russia tested nerve agent on door handles before Skripal attack, UK dossier claims Read more

The UK published previously classified intelligence claiming Russian military intelligence had targeted the email accounts of Sergei and Yulia Skripal since 2013 and had tested whether door handles could be used to deliver nerve agents. It said the highest concentration of the nerve agent found in Salisbury had been on the door handle.



The Russian ambassador to the UK said it would produce its own dossier setting out an alternative version of what had happened in Salisbury.



The Russian defence minister, Maj Gen Igor Konashenkov, claimed to have direct evidence that Britain had orchestrated the alleged chemical attack at Douma in Syria. The UK, he said, was “directly involved in the provocation”.

Although the US ambassador to the UN Nikki Haley said no decision has yet been taken on military action, the White House said it had “a high level of confidence” that the Syrian regime carried out the chemical weapon attack in Douma.

The US, UK and France continued to build up military resources in the eastern Mediterranean.

The fresh claims about the Salisbury attack were made in a letter from Sir Mark Sedwill, the UK’s national security adviser, to the Nato secretary general, Jens Stoltenberg. It is extremely rare for the UK to make such intelligence public.

The decision to go public was prompted by the UK coming off second best over the last few weeks in the war of words with Russia over responsibility for the attack. The surprise move by the intelligence agencies, who usually jealously guard their information, escalates tensions with Russia.

In his letter, Sedwill, who has an overview of the work of all the British spy services, said: “I know that Nato will remain seized of the need to confront the increasingly aggressive pattern of Russian behaviour of which the attack in Salisbury was an acute and recent example.”

His letter filled in some of the intelligence that Theresa May referred to when she made a House of Commons statement saying Russia was “highly likely to have been behind the attack.

In response, the Russian ambassador in London, Alexander Yakovenko, who seemed to be caught on the hop by the Sedwill letter, announced that the embassy would be publishing its own report on the attack.

“The British government still hasn’t produced any evidence in support of its position that would confirm their official version,” he told a press conference, at which he showed footage of Tony Blair apologising for intelligence mistakes made in the run-up to the Iraq war. “We get the impression the British government is deliberately pursuing the policy of destroying all possible evidence.”

In his Nato letter, Sedwill said the nerve agent novichok had been developed at the Russian research facility in Shikhany as part of an offensive chemical weapons programme with the codename Foliant.



Sedwill said Russia regarded at least some of its defectors as “legitimate targets for assassination”, with the suggestion that they could include Skripal, a former member of the GRU, Russian military intelligence, who was convicted by Russia of espionage in 2004 after working for MI6.



Syria crisis: how we got here and where do we go next? Read more

“We have information indicating Russian intelligence service interest in the Skripals, dating back at least as far as 2013, when email accounts belonging to Yulia Skripal were targeted by GRU cyber specialists,” Sedwill wrote.

“During the 2000s, Russia commenced a programme to test means of delivering chemical warfare agents and to train personnel from special units in the use of these weapons. This programme subsequently included investigation of ways of delivering nerve agents, including by application to door handles. Within the last decade, Russia has produced and stockpiled small quantities of novichoks under the same programme.”

He said Russia had continued developing small amounts of novichok over the past decade.

“Russia’s chemical weapons programme continued after the collapse of the Soviet Union,” he added. “By 1993, when Russia signed the chemical weapons convention (CWC), it is likely that some novichoks had passed acceptance testing, allowing their use by the Russian military.

“Russia’s CWC declaration failed to report any work on novichoks. Russia further developed some novichoks after ratifying the convention. In the mid-2000s, President [Vladimir] Putin was closely involved in the Russian chemical weapons programme. It is highly unlikely that any former Soviet republic (other than Russia) pursued an offensive chemical weapons programme after independence. It is unlikely that novichoks could be made and deployed by non-state actors (eg a criminal or terrorist group).”

Quick guide What is novichok? Show Hide Novichok refers to a group of nerve agents developed by the Soviet Union in the 1970s and 80s to elude international restrictions on chemical weapons. Like other nerve agents, they are organophosphate compounds, but the chemicals used to make them, and their final structures, are considered classified in the UK, the US and other countries. The most potent of the novichok substances are considered to be more lethal than VX, the most deadly of the familiar nerve agents, which include sarin, tabun and soman. Novichok agents work in a similar way, by massively over-stimulating muscles and glands. Treatment for novichok exposure would be the same as for other nerve agents, namely with atropine, diazepam and potentially drugs called oximes. The chemical structures of novichok agents were made public in 2008 by Vil Mirzayanov, a former Russian scientist living in the US, but the structures have never been publicly confirmed. It is thought they can be made in different forms, including as a dust aerosol. The novichoks are known as binary agents because they only become lethal after mixing two otherwise harmless components. According to Mirzayanov, they are 10 to 100 times more toxic than conventional nerve agents. Photograph: Matt Cardy/Getty Images Europe

The Organisation for the Prohibition of Chemical Weapons, which is linked to the United Nations, confirmed on Thursday that a novichok nerve agent had been used in the Salisbury attack.

Sedwill wrote: “I would like to share with you andallies further information regarding our assessment that it is highly likely that the Russian state was responsible for the Salisbury attack. Only Russia has the technical means, operational experience and the motive.”

The failure of the UK to release intelligence had left a vacuum that Russia had filled with various alternative explanations and scenarios for the attack. Hamish de Bretton-Gordon, a British chemical weapons expert, said he was delighted some of the intelligence had finally been made public, expressing regret it had not been done earlier.



“I think we had been losing the information battle and we had to get on the front foot,” he said.