This thesis is about the importance of nuclear weapons to Australian defence and strategic policy in Southeast Asia between 1953 and 1973. It argues that Australia's approach to nuclear issues during this period, and its attitude towards the development and acquisition of nuclear weapons in particular, was aimed exclusively at achieving narrowly defined political objectives. Australia was thus never interested in possessing nuclear weapons, and any moves seemingly taken along these lines were calculated to obtain political concessions - not as part of a 'bid' for their acquirement. This viewpoint sits at odds with the consensus position of several focused studies of Australian nuclear policy published in the past decade. Although in general these studies correctly argue that Australia maintained the 'nuclear weapons option' until the early 1970s, all have misrepresented the motivation for this by contending that the government viewed such weapons in exclusively military terms. The claim that Australia was interested only in the military aspect of nuclear weapons does not pay due attention to the fact that defence planning was based entirely on the provision of conventional forces to Southeast Asia. Accordingly, the military was interested first and foremost with issues arising from extant conventional planning concepts, and the government was chiefly concerned about obtaining allied assurances of support for established plans. The most pressing requirement for Australia therefore was gaining sway over allied countries. However, the Australian government was never in a position to overtly influence more powerful allies against an undertaking that could escalate into limited war, and was similarly incapable of inducing its allies to retain forces in the region in spite of competing pressures. It was for this reason that Australia would seek to manipulate the nuclear weapons option. Indeed, access to such weapons offered Australia the opportunity to achieve greater integration in formulating allied planning, while the threat to manufacture them provided a means of convincing regional partners to maintain a presence in the area. The thesis therefore concludes that Australia carefully presented its options for procuring nuclear weapons to gain influence over its allies in response to strategic developments in Southeast Asia.