By late 1917 it was clear to Walpole and to the British authorities that there was little advantage in keeping him in Russia. On 7 November he left, missing the Bolshevik Revolution, which began on that day. He was appointed to a post at the Foreign Office in its Department of Information, headed by John Buchan. Soon after returning he volunteered for the British army, but, as expected, failed the necessary medical examination because of his poor sight. He continued to work in British propaganda when the department was reconstituted under Lord Beaverbrook in April 1918, and remained there for the rest of the war and beyond, resigning in February 1919. Little is known about what he wrote for the department, as most of its records were destroyed after the war, but he noted in his diary that he had written the department's official report to the War Cabinet: "a beastly job – the worst I've ever attempted". For his wartime work he was awarded the CBE in 1918.