The theories which might be true about the novichok poisoning of Sergei and Yulia Skripal – and the ones which definitely aren't

One believable explanation is that the attempt on Sergei Skripal’s life was in revenge for comrades he had betrayed to MI6, for money, after becoming a double agent. But even that has its major flaws

The latest twist in the novichok attack in Salisbury – the disclosure of the photographs of the two suspects and the names they were using – has continued the extraordinary drama surrounding an act as brutal as it was unexpected.

As has happened with other developments in this case, the revelation has been accompanied by recriminations, threats and conspiracy theories. It has also ratcheted up the confrontation between Britain and Russia to another incendiary level, with the accusation that the Kremlin has committed an act of war in this country.

The UK government remains adamant that Moscow is responsible for the attempted assassination of Sergei Skripal and his daughter Yulia. It is believed that the real identities of Alexander Petrov and Ruslan Boshirov have now been established by British security agencies and this has proven that they are serving officers in the GRU, the Russian military intelligence service

These details as well as other information, gathered through a variety of methods of intelligence, have been passed on to allied countries, with the latest instalment delivered just before the issue was addressed at a highly charged session of the United Nations Security Council.

It was the contents of this intelligence which, according to a number of diplomatic sources, led to the US and other Western states joining the UK in a vociferous condemnation of Russia. This support would not necessarily have been automatic, the diplomats point out, had the information provided not been strong and persuasive. It should be noted, however, that Italy’s populist government did not join in with denouncing Moscow.

The mood in Europe is not for further confrontation with Russia; if anything, it’s more opposed to escalation than it has been in a long time. Germany is continuing, despite pressure to the contrary from the US and UK, with Nord Stream 2, which will transport Russian gas to Germany, bypassing the Nato Baltic states. Emmanuel Macron stressed to French diplomats last month that the Cold War must not restart and there needs to be dialogue with Moscow on a range of issues from chemical weapons, cybersecurity, missile proliferation and polar region environment. A swathe of central European countries – Hungary, Austria, and the Czech Republic – have been vocal about closer ties with Russia.

It remains to be seen how long it will be before the British authorities put further details about the Salisbury suspects in the public domain. What came out earlier this week was withheld for a time in the hope that the two men, unaware that their roles had been discovered, would travel to an allied country where they could be arrested.

But, as to be expected with an investigation of such size, there were rising reports of a breakthrough and, in the end, the decision was taken to release the material. A European Arrest Warrant has been issued, but there is no expectation of the suspects now voluntarily going into a country where it can be activated. And there is next to no hope that Vladimir Putin’s government will extradite the pair.

There has, meanwhile, been endless theorising in the media about the nature of the attack – that novichok was inadvertently brought in by Yulia Skripal on her clothing or, in another version, a bag of sweets; that Yulia was the real target after “a bust-up with her boyfriend’s mum because he said they were starting a family” (the woman was supposedly a high-ranking Russian official); that the novichok was put into the Skripals’ drinks in a pub; that the breakthrough in identifying suspects came after the “chilling” content of an electronic message to Moscow that was picked up by a junior personnel at an RAF station in Cyprus saying: “The package has been delivered” (the account was dismissed by GCHQ and other security and intelligence agencies).

Then, after Salisbury resident Dawn Sturgess sadly died after coming into contact with novichok remnants from the Skripal attack, came the tale that teams of Russian agents had been making “dead drops” of the nerve agent all over the city in preparation for the attack; and that there was a “new lead” of “a giant crop circle” showing “the symbol of chemical weapons” spotted just hours before the death.

At his prolonged press conferences earlier this year, the Russian ambassador in London, Alexander Yakovenko, would accuse MI5, MI6 and the CIA of deliberately planting these stories. He was unaware, perhaps, of the vagaries of the British media. The Russians themselves produced around 20 different versions of what had happened, ranging from attempted suicide and an accidental overdose to a “false flag operation” carried out by the British (to possibly distract attention from the disaster of Brexit) or the Americans, or the Ukrainians or the Swedes or Russian émigrés.

The British government has so far failed to provide a direct motive for the attack on the Skripals. Sergei Skripal had been released in a spy swap in 2010 and had been living openly under his own name in this country since then. Other Russians who were part of that exchange continue to live similarly openly, in this country or elsewhere, without facing any threats.

The only explanation – one arrived at by default – is that the attempt on Sergei Skripal’s life was in revenge for comrades he had betrayed to MI6, for money, after becoming a double agent. But there is no explanation why this should happen so many years later, breaking in the process the traditional rules of a spy swap. The timing of the act, with all the adverse publicity it would attract, just when Russia was about to host the World Cup – and as has been repeatedly and understandably pointed out – makes no sense.

There have been claims that Skripal may have continued in the spying game. It is true that he had been giving talks, in this country and abroad, for a while. But security sources are adamant that these are about his experiences in the field and, as such, are necessarily dated. One person who went to one of his lectures at a British military facility on the south coast described it as “generally historic and anecdotal.”

Skripal’s travels had taken him to the Czech Republic and Estonia, where he had been involved in seminars with intelligence officials. There are conflicting reports about what he was able to tell them; but the general consensus is that it was not anything earth-shattering, certainly nothing important enough to sign a death warrant.

Skripal had also been visiting Spain, where he was recruited by MI6, with reports that he had been helping the country’s CNI intelligence services. Alexander Litvinenko, another former Russian intelligence officer, had been helping the Spanish authorities to look into alleged links between Russian organised crime and the Kremlin – of interest because of the presence of the Russian mafia in the Iberian peninsula – before he was murdered in London 12 years ago.

This is one of a number of parallels between the Litvinenko and Skripal cases. Others include the use of highly unusual materials (polonium and novichok); two-man teams – Andrei Lugovoi and Dmitry Kovtum, who were accused murdering Litvinenko, and the men using the names Petrov and Boshirov in Salisbury – flying in to carry out the attack; as well as trails of radioactive isotopes and nerve agents found in the respective investigations.

These similarities would seem to indicate links, albeit circumstantial, between the two cases. But Spanish and British officials are adamant that Skripal was not providing information in any specific investigation to Madrid.

There will be further revelations about the Salisbury attack – but major questions remain unanswered. There is little doubt that numerous theories will continue to circulate about what lay behind novichok coming to a provincial English city with such devastating consequences.