This thesis describes the political-military alliance of the Warsaw Treaty Organisation (WTO) from its origins and founding in 1955 to its 30th Anniversary in 1985, and after. In showing how the WTO has developed and operated, its practical application in the fields of joint foreign policy and military affairs is described and discussed. In the light of this analysis, the WTO is placed in its context within the socialist community. The origins of the WTO are shown to be part of a general trend towards closer co-operation between the European socialist countries. The states were formally brought together as a public response to the London and Paris Agreements of 1954, which officially rearmed the Federal Republic of Germany and incorporated it into the Western military alliance system and NATO. The structural development is described and analysed, showing the practice of the official structure largely to be a response to existing ad hoc arrangements. The limitations placed on the Organisation's political and military roles are explained, detailing how the WTO is formally restrained from operating as an efficient or effective multilateral co-ordinating body. Where it does operate, the WTO is shown principally to be a political organisation. The documentary history of the WTO is analysed, to show how the structure works in practice. Particular stress is placed on the role of the WTO in carrying out its claimed purpose of co-ordinating the foreign policies of the members. The conclusion is suggested that the WTO at most co-ordinates the `basic principles' rather than the diplomatic practice of its members' foreign policies. The participating states are shown not to be significantly bound by the WTO in the practice of their national foreign policies, though they are bound by bilateral factors external to the structure of the Warsaw Treaty. The 30th Anniversary of the signing of the WTO, potentially a historic landmark, is shown to have passed with very little pomp or celebration. The treatment of the Anniversary in the Soviet Union and amongst its allies was low-key. The issues covered by the Anniversary speeches and articles are described, and are analysed both for what they said about the WTO, its origins, practice, ansd significance, and for what was not said or done. Changes are analysed that have taken place under the new Soviet leadership of Mikhail Gorbachev, whose accession occurred just before the signing of the Protocol extending the Treaty. The 30th Anniversary soon followed. Structural changes were hinted at but never took place, though the documents issued by the existing bodies have become much more open in their description of the discussions and disagreements that took place. These events, coinciding with other changes in Soviet internal and externalpolicies, were shown to be part of an apparent attempt by the Soviet authorities to consult and co-ordinate its actions with its allies, or at least to appear to be doing so. It is also shown where past practices, such as unilateral Soviet moves on foreign policy and arms control, have not changed. The conclusion is that the real significance of the WTO is ideological, serving to give the impression of unity. The Warsaw Treaty Organisation is just another means in the many forms of alliance indicating, and used to justify, the `socialist community'. Other forms of alliance, both political and military, take precedence over the WTO in all its functions. These are principally bilateral, rather than multilateral, forms, and in many cases they are party, rather than state, forms of alliance. Research into the WTO has not been fruitless, but has proved to be the study of issues other than the foreign or defence policies of a multilateral alliance.