Reuters in London. During his time in London, Jacob moved in high social and intellectual circles. He wrote a play in which the hero was a communist and as a result, decided to read Das Kapital. In 1934, he married Iris Morley, daughter of Lieutenant Colonel Chartres Morley. She was a historical novelist and journalist for The Observer and the Yorkshire Post. Early in their marriage, they bonded amidst the Great Depression and hunger marches. This period stirred up socialist sentiments in the couple. In 1936, the Jacobs went to Washington where he was in regular and close contact with US President Franklin D. Roosevelt. They stayed in Washington until the outbreak of World War II, when they returned to London. War correspondent Jacob remained in London until May 1941 when became a war correspondent for the Daily Express. He sailed to Cairo, taking the long sea route via Cape Town. He spent the next two years with the 8th Army in North Africa, initially covering the Siege of Tobruk and Operation Crusader. He was withdrawn from Tobruk shortly before it fell to the Germans and was posted to Tehran where he received permission from the Soviet Embassy to visit the Red Army in Azerbaijan. He returned to Egypt for the first and second Battle of El Alamein, before traveling to India. He covered Wingate's first 'Chindit' expedition in Burma, and the circumstances of Gandhi's fast. In the Soviet Union for four months, he covered the Battle of Kursk and Stalin's counterattack. He described his experiences in A Traveler's War published in 1944. After Christmas leave in England in 1943, Jacob and Iris sailed to the Soviet Union in January 1944 on board a ship of the Arctic Convoy. They spent the remainder of the war in Moscow, covering the advances of the Red Army in Odessa, the Crimea, and through Vitebsk, Minsk, Poland, and on to the fall of Berlin. He published A Window in Moscow in 1945. His experiences made him sympathetic towards the Soviet regime and he stayed in the Soviet Union, on and off, until the start of the cold war in late 1947. Iris had become a Communist and her ideas strongly influenced him. He suspected that her membership of the Communist Party worked against him even when they were separated, and that he was blacklisted by the BBC and put on their "Christmas tree"