Scheme, but Australia was not a party to the 1948 Modus Vivendi, the nuclear agreement between the US and UK which superseded the wartime Quebec Agreement. This cut Australian scientists off from technical information to which they formerly had access. Britain would not share it with Australia for fear that it might jeopardise the far more important relationship with the United States, and the Americans were reluctant to do so after the Venona project revealed the extent of Soviet espionage activities in Australia. The creation of North Atlantic Treaty Organization (NATO) in 1949 excluded Australia from the Western Alliance. On 3 October 1952 the United Kingdom tested its first nuclear weapon in Operation Hurricane in the Montebello Islands off the coast of Western Australia. A year later the first nuclear tests on the Australian mainland were carried out in Operation Totem at Emu Field in the Great Victoria Desert in South Australia, with a detonation on 15 October and a second two weeks later on 27 October. The Australian Minister for Supply, Howard Beale, stated in 1955 that "England has the know how; we have the open spaces, much technical skill and a great willingness to help the Motherland. Between us we should help to build the defences of the free world, and make historic advances in harnessing the forces of nature." Maralinga site Selection Neither the Montebello Islands nor Emu Field were considered suitable as permanent test sites, although Montebello was used again in 1956 for Operation Mosaic. Montebello could be accessed only by sea, and Emu Field had problems with its water supply and dust storms. The British Government's preferred permanent test site remained the Nevada Test Site in the United States, but by 1953 it was no closer to securing access to it than it had been in 1950. When William Penney, the Chief Superintendent Armament Research, visited South Australia in October 1952, he gave the Australian Government a summary of the requirements of a permanent test site. In May 1953, the UK Chiefs of Staff Committee were advised that one was needed. They delegated the task of finding one to Air Marshal Sir Thomas Elmhirst, the chairman of the Totem Executive (Totex), which had been formed in the UK to coordinate the Operation Totem tests. He wrote to J. E. S. Stevens, the permanent secretary of the Australian Department of Supply, and the chairman of the