Litvinenko was himself a member of Russia’s FSB, the successor to the nefarious KGB, but it was because of his public accusations that his own government ordered the assassination of Russian tycoon and oligarch Boris Berezovsky that ultimately saw him arrested multiple times, forcing him to defect to the United Kingdom in 2000.

“The view inside our agency was that poison is just a weapon, like a pistol,” Litvinenko told the New York Times in 2004, two years before his assassination. “It’s not seen that way in the West, but it was just viewed as an ordinary tool.”

Once in the UK, Litvinenko wrote two books detailing Vladimir Putin’s involvement in what may have been a false flag terror attack (blamed on Chechen separatists) that helped ensure Putin’s accession to the nation’s highest office. He also had a slew of other things to say, and he publicly accused Putin of ordering the assassination of Russian journalist Anna Politkovskaya in 2006.

That last act of defiance may have been the final straw, as less than a month later Litvinenko fell critically ill. For 21 days, he remained hospitalized as each of his major organs shut down one after another — the culprit was acute radiation poisoning caused by exposure to polonium-210, an extremely rare and highly radioactive substance that was a critical component of early Soviet nuclear bombs.

It seemed clear, then, that the polonium poisoning of Litvinenko was intended as a clear message from Vladimir Putin: cross him, and the repercussions will be dire.

Alexander Perepilichny

That count of assassinations linked to the Russian government also does not include suspicious deaths with links to the Kremlin, like that of Alexander Perepilichny, a 44-year-old Russian man that was found dead inside the gated London community he lived in. London police ruled out foul play despite raised concerns that his death may have been caused by a difficult to detect poison substance from the gelsemium plant. Perepilichny had fled to the UK after assisting with an international investigation into Russian-based money laundering.

To date, the cause of his death in 2012 has not yet been officially determined.

Vladimir Kara-Murza

In 2015 and again in 2017, Russian opposition activist Vladimir Kara-Murza was hospitalized after exhibiting signs of poisoning.

“In the space of about 20 minutes, I went from feeling completely normal to having a rapid heart rate, really high blood pressure, to sweating and vomiting all over the place, and then I lost consciousness,” Murza told reporters in 2016.

Laboratory analysis of his blood work found elevated levels of mercury, copper, manganese and zinc in him in both instances, and again, Moscow denied involvement in the effort.

“I knew straightaway what it was because this was the second time in two years that this happened, and it, and it began almost identically in the same way,” He told NBC after the second poisoning attempt. He survived both incidents, keeping him off of the list of Russian state-sponsored assassinations for the time being.

Viktor Yushchenko

Viktor Yushchenko was a Ukranian opposition candidate running for president within his nation when he suddenly fell mysteriously ill. His face was soon covered in lesions, crippling pain attacked his back and abdomen, and the left side of his face became paralyzed. When he re-emerged in the media, he was a distinctly changed man, apparently as a result of dioxin poisoning.

Yushchenko, it’s worth noting, was a pro-West candidate running against the Pro-Russian Yulia Tymoshenko. He would ultimately end up winning a messy election, before being removed from power as a result of protests soon thereafter.

“If someone put a drop of pure dioxin in his food, he wouldn’t taste it, he wouldn’t see it and a few days later he’d start to get sick,” Arnold Schecter, a dioxin expert at the University of Texas School of Public Health at Southwestern Medical Center in Dallas, said.

“If you are trying to kill someone quickly, it’s not the way to go, but if you want to disable someone and want to do it subtly and have it happen days or weeks or months after you have contact with someone, this can do it,” Schecter said. “Plus there are very few labs in the world that can accurately detect dioxin in the blood.”

And so many more…

This is hardly a conclusive list of Russian-linked assassinations and attempts. In fact, it may be impossible to know how many times the Kremlin has utilized poisoning in one form or another to silence critics or affect change in foreign governments. Stories from people like Anna Politkovskaya, a journalist that covered Russia’s invasion of Chechnya, who suddenly fell ill after drinking tea that apparently contained poison. She would later be murdered in the elevator of her apartment building.

Karinna Moskalenko was prevented via poisoning from returning to Moscow to attend part of the murder trial that, ironically enough, was for the killer of the aforementioned journalist Anna Politkovskaya. Alexander Litvinenko claimed that her murder was conducted under Putin’s direct orders. After Moskalenko fell ill and canceled her trip, her husband discovered Mercury pellets under the seat of her car.

The list of these incidents goes on and on, which should come as no surprise. As Litvinenko pointed out, the Russian intelligence community sees poison as an effective tool to eliminate threats to their foreign policy and to intimidate those who would betray the Kremlin. When one takes a step back and looks at the broader use of poisoning, even exotic poisons that seem to point the finger directly at Moscow, the recent incident in Salisbury, England no longer seems like an isolated incident, but rather the latest in a long-standing policy employed by Putin’s regime.

The real question, then, is… will anything be different this time around? Only time will tell.

Modified feature image courtesy of the Associated Press.