Thwaites joined the
Royal Naval Volunteer Reserve and was an officer in
World War II. In 1999 he published
Atlantic Odyssey, an account of his war service on anti-submarine escort
naval trawlers and an armed
whaler. After the war he returned to Oxford to complete his studies, graduating MA B Litt, then returned to Australia, becoming a lecturer in English at the University of Melbourne in 1947. Despite having no background in intelligence work, Thwaites was recruited in 1950 to the
Australian Security Intelligence Organisation (ASIO) by its director-general
Charles Spry. Unlike the British tradition of university recruitment, in 1950 almost all ASIO staff were from military intelligence and police operational backgrounds, and Spry had been encouraged to recruit senior staff with higher educational credentials. Thwaites proved to be a highly competent intelligence officer and encouraged more analytical recruitment policies. Despite some outside criticism that ASIO staff was an "old boys' club" (perhaps based on the assumption that ASIO was modelled on MI5), military and police backgrounds dominated ASIO staffing into the 1970s and Thwaites eventually resigned believing that the analytical resources were undervalued. In 1954 Thwaites played a leading role in the defection of the
Soviet diplomat
Vladimir Petrov to Australia, which led to the celebrated
Petrov Affair. When Petrov first defected it was Thwaites who debriefed him, and he later spent 18 months with Vladimir and Evdokia Petrov at an ASIO "safe house" in
Sydney, helping them write their life stories in the book "Empire of Fear". Thwaites always insisted that the timing of Petrov's defection was determined by Petrov, and was not orchestrated to coincide with the 1954 federal election, as the
Labor Party leader, Dr
H. V. Evatt said at the time and as many people in Australia continued for many years to believe. He also maintained that Petrov was a genuinely important source of intelligence in the
Cold War context, revealing the names of about 600 Soviet operatives around the world. Thwaites recorded his part in these events in
Truth Will Out: ASIO and the Petrovs. ==Literary life and career==