After the Second World War, the Americans and the British showed increasing reluctance to share their secret intelligence with Australia. Technical operations and Soviet defectors had revealed conclusively that high-level penetration agents, or “moles”, operating in Australia, were betraying classified intelligence to Soviet intelligence officers. Ben Chifley’s Labor government was persuaded by Australia’s allies to set up a security and counter-espionage service along the lines of Britain’s MI5. In 1949, the Australian Security Intelligence Organisation (ASIO) was established, albeit with strong opposition from the Left. The Venona Project was the name given to the secret decryption by US and British…