Moscow's announcement Friday of expelling six British diplomats for alleged espionage has drawn a strong rebuke from the United Kingdom while also intensifying animosity between Russia and the West over the war in Ukraine.
However, the six are but a small number in the history of Moscow-London acts of expulsion, which have a record of angry bursts over the past decades. Both sides have expelled more than 20 at a time — and in one case, more than 100.
The expulsions are frequently tit-for-tat moves, with one side retaliating for the act of the other, something Russian diplomatic language calls a “mirror answer.”
Here is a look at some major acts of expulsion between London and Moscow:
Sergei Skripal, a Russian intelligence officer who was a double agent for Britain, was severely poisoned along with his daughter in Salisbury, where he had settled after being released by Russia in a 2010 prisoner swap. The poison was identified as Novichok, a Soviet-developed nerve agent.
A week and a half after the Skripals were discovered in grave condition, British Prime Minister Teresa May declared Russia to be responsible for the attack and ordered the expulsion of 23 diplomats. Russia then expelled an equal number of Britons.
Oleg Gordievsky was the KGB's station chief in London, but had been passing along information to British intelligence for years. He was called back to Moscow for consultations in 1985 and decided to go despite fears that his role as a double agent might have been exposed.
He was interrogated but not charged, and Britain arranged an undercover operation to spirit him out of the Soviet Union. In the aftermath of the operation, Britain used information from Gordievsky to expel 25 Soviet diplomats. Moscow retaliated two days later with the same number.
In an effort to curb suspected widespread espionage by Soviet diplomats and even their wives, British agents managed to recruit a member of the Soviet trade delegation who was also a KGB operative. The agent, Oleg Lyalin, provided extensive information identifying others working for the KGB.
Britain hesitated to act on the information, concerned it could jeopardize international talks that were underway on the status of the divided city of Berlin. After the talks concluded, the U.K. announced that 90 Soviet officials would be expelled and 15 others who were out of the country at the time would not be allowed to return — 105 in all.