In 1991, independent Ukraine entered the international system of states with many drawbacks: in addition to lacking the legitimacy provided by prolonged periods of sovereignty, Ukraine suffered from economic over-dependence on Russia and was weakened by internal political and social cleavages. This thesis argues that in order to tackle the threats to its sovereignty, the new state adopted a foreign and security policy with two key objectives. Firstly, Kyiv sought to establish bilateral ties with all regional neighbours. Secondly, along the Western azimuth Kyiv established the 'strategic objective' of integration with the European Union via membership of subregional institutions. The desire to integrate with Western institutions implied a reluctance to integrate more deeply with the Commonwealth of Independent States (CIS) along the North-eastern azimuth. However, the nature of Ukraine's ties with Russia meant that relations between them came to dwarf Kyiv's relations with neighbours along the Western azimuth. Thus it is argued that Ukraine's foreign policy was conceived as an attempt to balance the demands of these two azimuths. Along the Southern azimuth relations with Black Sea littoral states provided a means for Ukraine to consolidate its independence- bilateral, subregional and regional objectives along the Southern azimuth were to complement goals along the Western vector, while simultaneously preventing Ukraine's re-integration along the North-eastern azimuth. The thesis concludes that although Ukraine failed to fully integrate with key subregional and regional institutions along its Western azimuth, by the end of its first decade of independence, its security was enhanced thanks to bilateral, subregional and regional relations along that azimuth. Furthermore, although it failed to fully avoid integration with the CIS along the North-eastern azimuth, by the end of 2000 Ukraine remained anything but a fully-fledged member of the CIS. The achievement of objectives along the Southern azimuth facilitated the respective achievements along the Western and North-eastern azimuths. The thesis also explored theoretical contributions to an understanding of Ukraine's regional aspirations on three analytical levels. Amongst the systemic theories, it was concluded that the robustness of the realist approach continues to present a formidable challenge to newer pretenders. However, with its greater allowance for the economic aspects of international relations, complex interdependence also maintains its explanatory power. As for regional level theories, although neofunctionalism provides some insight into Ukraine's regional behaviour, as does neoliberal institutionalism, both struggle to provide a coherent and consistent explanation along all three azimuths. While the normative 'subregional' regionalist approach is limited by the contradictory demands of regional and subregional institutions, the emphasis placed on the politico-economic aspect of regionalism by New Wave regionalists has extended our understanding of regionalism. The domestic level of analysis indeed revealed a relationship between Ukrainian regional prospects and the ongoing democratization process.