This dissertation comparatively analyses the use and effectiveness of international mediation by the United Nations and six regional organisations namely, The League of Arab States (AL), the Association of South East Asian Nations (ASEAN), the European Union (EU) the Organisation of American States (OAS), the Organisation for African Unity (OAU) and the Organisation for Security and Cooperation in Europe (OSCE). When reviewing the literature it became evident that a comparative expose of organisation mediation was overdue. Research on international mediation posits that mediation success is contingent on several contextual and process factors. This thesis sought to determine which of the contextual factors affecting international mediation also influenced organisation mediation. Secondly, similarities and differences between UN and regional organisation mediation are identified and examined.

In addition to considering the effect of contextual factors on mediation, the analysis takes into consideration the impact of various levels of interorganisational cooperation. The UN and regional organisations are obligated to cooperate in the peaceful settlement of international disputes, however very little is known about the effectiveness of their joint mediation efforts. Indeed, the nature of interorganisational relations in international mediation has never been empirically examined. Taking into account actual mediator experiences, inter organisational mediation activities are categorised to reflect three different levels of cooperation: independent participation, coordination and cooperation. This research takes a unique look at the impact of organisation cooperation on mediation to gain more insight into how organisations function in a 'mediating relationship'. The analysis leads to a re-evaluation of systemic cooperation once the reality of interorganisational cooperation is revealed.

This study enlarges an extensive data set of international mediation to analyse specific elements of organisation mediation. New data was coded to comply with the existing data set and was fitted to' conform to the framework of the contingency model. The empirical analysis, using bivariate and multivariate methods, identifies several organisational characteristics and differences. While this study does not provide definitive answers on how to apply mediation more effectively, the results have some predictive value in determining the strengths and weaknesses in organisation mediation practices. Findings suggest that though the UN and regional organisations mediate effectively in different dispute conditions, cooperative mediation offers the greatest potential. Despite the intense conditions in which cooperation occurred and the fact that organisation cooperation is still largely ad hoc, lacking structure and recognition, cooperative mediation was remarkably successful.