During the First World War, he was seconded to the Foreign Ministry in Petrograd, Russia, where he reported political events back to London, and worked in propaganda.

[4] They had three sons, Peter (who became a diplomat), Andrew (who became a soldier) and Richard (a historian), and two daughters, Elizabeth, who was Head of the Foreign Research and Press Service, Baltic Section at Chatham House during WWII and Ursula (Susan), who married Sir Geoffrey Jellicoe, the landscape architect, becoming an eminent plantswoman and photographer in her own right.

[9] Reputed to be the products of the Faberge workshop, these are currently on display in the foyer of the School of Slavonic and East European Studies building at University College London.

[9] With the outbreak of World War I, Pares was appointed official observer to the Russian army[7] and later seconded to the staff of the British Embassy in Petrograd.

[citation needed] Pares set his hopes for Russia with the Provisional Government and, after the Bolshevik revolution, moved to Siberia to support Alexander Kolchak's army where he gave frequent lectures to the White troops.

In 1939, Pares retired as Director, subsequently acting as an adviser to the wartime government on Russian affairs, taking a favourable attitude toward Stalin, while deploring some of his excesses.