On the outbreak of the Second World War, he joined the Royal Air Force and was commissioned as pilot officer in June 1940. However, he was asked to leave, and it was suspected that this was due to his communist sympathies. After the Soviet Union was invaded by Germany, the military was more willing to accept communists. According to Platts-Mills own account, Sir Stafford Cripps introduced him to prime minister Winston Churchill, who told him: "I have been teaching the British since 1918 that the Russians eat their young. For the sake of the war effort, take as much money as you need and change that public perception of them." During the later part of the war, Platts-Mills volunteered to work as a Bevin boy in the coal mines. Then 38, he worked in the mines for 18 months.
