This thesis seeks to analyze the role of regional organizations, specifically the European Union in dealing with external crisis. Furthermore, the research will focus on the development of EU treaties and mechanisms that influenced its foreign policy and security and defense policies in the context of foreign intervention. This study will target two considerations that are required for international involvement. Two case studies, which are the Kosovo Crisis and Ukraine Crisis, will be compared to reflect on the considerations that affected the European Union decision to intervene and the different ...