Extract relating to military intelligence work:
Jonathan Cohen was educated at St Paul’s School, London where he excelled at mathematics and classics. He went up to Balliol College, Oxford, in 1939 planning to read Greats. But after four terms at Balliol he was recruited in 1941 to Bletchley to learn cryptography and Japanese. He served from 1943 to 1945 as a Lieutenant in the Royal Navy assigned to listening and decoding stations maintained by Naval Intelligence first in Mombasa and then in Colombo. Cohen, with another cryptographer and lifelong friend, Hugh Denham, together explored the jungles of Ceylon on bicycles. On one leave, he and Denham travelled to North India and Nepal, and trekked over the mountains into Tibet.
At the end of the war, Cohen decided against accepting an opportunity to join the Foreign Service. In mid-November of 1945, he returned instead to Balliol.