This chapter examines two dimensions of EU efforts regarding peacekeeping and peacebuilding. The first dimension is to highlight the EU role within EU bloc that was formerly called the EC. This dimension explores what are the imperatives of European ambition to resolve the inter-bloc disputes, conflicts and rivalries. This study entails that EU has been working hard for conflict resolution within the bloc, including Franco-German rivalry and ethno-national disparities of Northern Ireland. Second, this chapter underlines the role of EU in other European crises such as Yugoslav crises that turned the EC towards peacemaking during early and mid-1990s.