In September 2014 , the FSB crossed into Estonia and abducted Eston Kohver , an officer of the Estonian Internal Security Service . Brian Whitmore of Radio Free Europe stated that the case " illustrates the Kremlin 's campaign to intimidate its neighbors , flout global rules and norms , and test NATO 's defenses and responses . " On 4 March 2018 , Sergei Skripal , a former Russian military intelligence officer who acted as a double agent for the UK 's intelligence services in the 1990s and early 2000s , and his daughter Yulia were poisoned with a Novichok nerve agent in Salisbury , England . The UK Prime Minister Theresa May requested a Russian explanation by the end of 13 March 2018 . She said that the UK Government would " consider in detail the response from the Russian State " and in the event that there was no credible response , the government would " conclude that this action amounts to an unlawful use of force by the Russian State against the United Kingdom " and measures would follow
were poisoned
Poisoning of Sergei and Yulia Skripal
Russia–European Union relations