Australia, and Menzies nominated Sir Frederick Shedden, the Secretary of the Department of Defence, as the person with whom Cassels should deal. At the time Britain was still Australia's largest trading partner; it would be overtaken by Japan and the United States by the 1960s. Britain and Australia had strong cultural ties, and Menzies was strongly pro-British. Most Australians were of British descent, and Britain was still the largest source of immigrants to Australia, largely because British ex-servicemen and their families qualified for free passage, and other British migrants received subsidised passage. Australian and British troops were fighting communist forces together in the Korean War and the Malayan Emergency. Australia still maintained close defence ties with Britain through the Australia New Zealand and Malaya (ANZAM) area, which was created in 1948. Australian war plans of this era continued to be closely integrated with those of Britain, and involved reinforcing the British forces in the Middle East and Far East. Australia was particularly interested in developing atomic energy as the country was then thought to have no oil and only limited supplies of coal. Plans for atomic power were considered along with hydroelectricity as part of the post-war Snowy Mountains Scheme. There was also interest in the production of uranium-235 and plutonium for nuclear weapons. The Australian government had hopes of collaboration with Britain on nuclear energy and nuclear weapons, but the 1948 Modus Vivendi cut Australian scientists off from information they had formerly had access to. Unlike Canada, Australia was not a party to the Quebec Agreement or the Modus Vivendi. Britain would not share technical information with Australia for fear that it might jeopardise its far more important relationship with the United States, and the Americans were reluctant to share secret information with Australia after the Venona project revealed the extent of Soviet espionage activities in Australia. The creation of NATO in 1949 excluded Australia from the Western Alliance. The three-man survey party, headed by Air Vice Marshal E. D. Davis, arrived in Sydney on 1 November 1950, and embarked on , under the command of Commander A. H. Cooper, who carried out a detailed hydrographic survey of the islands. The charts at the Admiralty had been made by in August 1840. Soundings were taken of the depths of coastal waters to measure the tides, and samples of the gravel and sand were taken to assess whether they could