Traitors will kick the bucket,” Vladimir Putin said in a 2010 interview. “Trust me. These people betrayed their friends, their brothers in arms. Whatever they got in exchange for it, those thirty pieces silver they were given, they will choke on them.”

It’s hard to deny that he may have been talking specifically about Sergei Skripal, a former colonel in Russian military intelligence that had been convicted four years prior of selling state secrets to the British secret intelligence agency, MI6 for $100,000. In 2010, Skripal was once again on Putin’s mind, as he was granted asylum in the UK as a part of a larger spy-exchange orchestrated by the United States.

Soon after arriving at his new UK home, Skripal echoed the Russian’ president’s sentiments: “They will try to shoot me in the back of the head, but they might use poison,” he said in an interview. “They never forget. When I was at the KGB in the 1970s they were still chasing people who had betrayed them 30 years before.”

Of course, Putin’s regime aren’t just known for their tough talk. In 2006, Alexander Litvinenko, another former Russian agent that had relocated to the UK, died after a painful three week ordeal, as each of his internal organs failed one by one; the result of an apparent poisoning. The poison? Polonium 210, a radioactive isotope perfect for assassinations – it is extremely radioactive, but boasts a relatively short half life and limited range, providing a lethal dose to only the intended target. Despite the Kremlin’s denials, it seemed immediately apparent that not only was Litvinenko’s assassination on Putin’s order, but he wanted the death to be a statement.

Sergei Skripal, a former Russian Military Intelligence Colonel, was released in 2010 after being convicted of selling state secrets to the British. He was granted asylum in the UK, where he has lived ever since.

Last Sunday, Sergei Skripal and his 33 year old daughter became the latest victims of what appears to be an attempt by the Russian government to assassinate a former spy on foreign soil. According to police, the two were found unconscious on a bench in the city’s center before being rushed to the hospital where they remain in critical condition. Analysis of two victims and the scene of the crime confirmed that the incident involved the use of an illegal nerve agent.

The use of a nerve agent, rather than any other readily available means of assassination within the UK would seem, then, to be another intended message to those who would betray the Russian government.

Of course, Russia has formally denied any involvement in the attack, just as they have with similar incidents in the past, but the investigation into just what happened to Skripal and his daughter has prompted some UK officials to push for further analysis into a string of similar seeming deaths over recent decades – deaths that U.S. Intelligence Agencies say are linked directly the Kremlin as well.

During today’s Urgent Question on government policy in relation to Russia, and following the incident being investigated in Salisbury, I asked the Foreign Secretary to discuss with you a review by the National Crime Agency (NCA), or another appropriate entity, into 14 deaths that have not been treated as suspicious by the UK police, but have reportedly been identified by United States intelligence sources as potentially connected to the Russian state.” The chair of the home affairs select committee, Yvette Cooper MP, wrote to Home Secretary Amber Rudd on Tuesday.