Afghanistan represents one of the most complex mosaics of ethnic groups in the world and its contemporary history has been characterised by ethnic hierarchy. Pashtuns domination of the country and their discriminatory policies toward non-Pashtuns have had long-term effects in destroying inter-ethnic trust. The hierarchical relationships among ethnic groups have always been an obstacle to creating ethnic harmony even in the pre-war Afghanistan. The paper, by adopting 'ethnic security dilemma theory,' seeks to analyse how and why ethnicity in Afghanistan was politicised and morphed into fault line that finally surfaced in the form of civil war in 1990s. It will discuss the impacts of internecine war on inter-ethnic relations and explores the possible options to deal with the longstanding ethnic security dilemma. Being caught in an ethnic trap, the paper argues, only a meaningful powersharing mechanism can glue the future Afghanistan together.