(CNN)The saga in the English cathedral city of Salisbury has all the elements of a John le Carré thriller -- a double agent, a mysterious and potentially deadly toxin, Cold War leitmotifs, a confounded security service and a flummoxed state government.
In Salisbury, grist for conspiracy theorists, and an elusive truth
There is so much grist in the story for conspiracy theorists and, as the truth may never truly be known, it has only compounded the mystery of the events that transpired on Sunday, March 4.
That afternoon, former Russian spy Sergei Skripal and his daughter Yulia were found unconscious on a shopping center bench and were taken to hospital. The pair remain in critical condition.
British police say the father and daughter were targeted specifically.
The police officer who first found them, since identified as Detective Sgt. Nick Bailey, remains in a serious condition, prompting concern for his safety from UK Prime Minister Theresa May among others.
But while many have been quick to blame Moscow, and in particular the Kremlin, for the attack, the overarching question remains: If indeed President Vladimir Putin sanctioned the attack, why did he?
And, if Skripal had been living out in the open for years in England without concern, why now?
"If the Russians want to get someone, they will get someone," said Alexey Muraviev, associate professor of national security and strategic studies at Curtin University in Perth, Western Australia.
"If we would assume, and we can only assume at this point, that the Russians decided to (do) this, it would have been achieved on the grounds to showcase again that whoever betrays Russia wouldn't feel immune or secure by being able to leave the country and settle in one of the western countries."
"He or she will not remain protected. If the decision is made, he or she will pay the ultimate price for betraying the country and that comes into the national psyche, that betrayal is betrayal."
In 2006 Sergei Skripal was sentenced to 13 years in prison for spying for Britain, according to Russian state media accounts of the closed media hearing.
Russian court officials at the time said he'd received at least $100,000 for his work for MI6, the British intelligence service. He was granted refuge in the UK after a high-profile spy exchange between the United States and Russia in 2010.
His daughter Yulia, 33, is thought to be one of the few members of his immediate family still alive after his wife and son died in recent years. She was visiting him from Russia at the time of the incident.
"The traitor's profession is one of the most dangerous in the world," said the anchor of a news program on Russia's First Channel in a broadcast on Wednesday.
"According to statistics, it is much more dangerous than a drug courier. Those who chose it rarely live in peace and tranquility to a venerable old age. Alcoholism and drug addiction, stress, severe nervous breakdown and depression are the inevitable occupational illnesses of the traitor. And as a result -- heart attacks, strokes, traffic accidents, and finally, suicide."
Linking the attack to Putin requires a "leap of imagination," says Dorothy Horsfield, a visiting fellow at the Australian National University College of Arts and Social Sciences. "How would he benefit? Creating chaos in Europe? Europe is doing a great job of that by itself."
More likely, Horsfield argues, is that this would have come from Russian non-state actors, similar to whoever might have carried out the attack on Alexander Litvinenko, a former Russian spy. He was poisoned by two suspected Russian agents at a London hotel bar in 2006 who were said to have spiked his tea with highly radioactive polonium-210.
A British public inquiry concluded in 2016 that Putin "probably approved" the killing, something the Kremlin denied. The two agents accused of the poisoning also denied their involvement.
If they went after Skripal, asks Horsfield, "why did they wait so long? The second thing is, which is entirely speculative, was he really living quietly in Salisbury? Litvinenko was up to all sorts of mischief, he was working with MI6 and liaising with the Spanish mafia and looking at the link there between the mafia and Russian intelligence agents."
Putin has spent far too much time and money trying to repair his image and raise himself to the "status of an internationally respected player" to do this now, argues Horsfield, author of "Russia in the Wake of the Cold War."
But she recognizes that this mystery requires a villain.
"There's a kind of Cold War assumption behind the idea that Putin is the big evil spider in the center of a web controlling these people," she said. "There's lots of links between retired and resigned intelligence operatives [working out of uniform]. One of Putin's greatest problems which he acknowledged in the recent state of the nation address was corruption. How do you control all this?"
The possibility that disgruntled former intelligence operatives might be behind the attack was one that Mark Edele, an expert in contemporary Russia, agreed was worth considering.
"My theory would be that there is somebody else involved. This guy has given away a lot of Russian agents in the West, so it's possible that this is payback from somebody who might or might not be in the FSB [Russia's successor agency to the KGB]," said Edele, from the School of Historical and Philosophical Studies at the University of Melbourne.
Given the nature of the weapon used, "clearly there's professionals behind this, it would make more sense to me." Another possibility, he said, was someone connected with organized crime in Russia came to track down Skripal, and found him in an English city of 45,000, which prior to March 4 had been better known as being nine miles from Stonehenge and having an original copy of the Magna Carta.
"If one thinks about the motivation, it's more likely that this is a revenge attack rather than one that goes straight back to the Kremlin. I feel that we might never know because the Kremlin's not going to tell us," Edele said.
Kremlin critics who believe Putin is behind the incident say this is the latest in the Russian leader's attempts to sow chaos on the continent and add further disruption within British society, which continues to struggle with the prospect of leaving the European Union.
"I would argue that Putin loves Europe, but his current strategy is to divorce Europe from the United States, to compromise the transatlantic connection, take Europe out from the US umbrella and put it under Russia's umbrella," said Alexey Muraviev.
"Putin loves Europe. He wants Europe to not be his, but certainly to be aligned side by side with Russia and the Russians continue to pursue Europe quite aggressively."
He says the frequent support Russia has shown for conservative right-wing political groups in Europe during recent elections, those who might be EU-skeptics, or less friendly towards the North Atlantic Treaty Organization (NATO), would sway politics in the region in Moscow's favor, with the hope that it would lead to a softening of harsh sanctions.
"Demonstrating to the Europeans that as long as you continue to support the US you'll be our target, creating this sense of fear among Europeans that their capitals are targets for nuclear-armed missiles," said Muraviev.
The Russian line, he said, is "we don't want to attack you, but if we feel threatened we'll retaliate immediately and that's part of effectively attempting to demonstrate to the Europeans that they're better off being neutral, because the US will get them into trouble."
The relationship between Moscow and London is more complex says Muraviev, particularly given the "special relationship" London has with Washington. That, and the repeated infringements on UK soil by Russia to hunt down defectors and ex-spies, has complicated diplomacy in recent years.
"London handles a number of Russian nationals who Russia wants home to face fraud charges, they're considered to be in political asylum in the UK," he said, providing another possible explanation of why this attack occurred.
Every day another development provides more material for conspiracy theorists to pore over. At least one tidbit of information might excite them: Salisbury, where the Skripals were attacked, is near Porton Down, a military research facility that specializes in testing chemicals used in war. There, experts are currently looking at samples of the substance that sickened so many in nearby Salisbury.