In 1971 during the Cold War, the UK expelled 90 Soviet diplomats suspected of spying. They'd been allowed into Britain in an attempt to improve relations, but it had been discovered that they'd been carrying out espionage instead. George Walden was a young diplomat on the Soviet desk in the British Foreign Office at the time. Photo: British Foreign Secretary Alec Douglas-Home (left) shakes hands with Soviet Foreign Minister Andrei Gromyko (right) at Heathrow Airport, 26th October 1970. (credit: Ian Showell/Keystone/Hulton Archive/Getty Images)