This book examines the role of multiethnic armies in post-conflict reconstruction, and demonstrates how they can promote peacebuilding efforts. The author challenges the assumption that multiethnic composition leads to weakness of the military, and shows how a multiethnic army is frequently the impetus for peacemaking in multiethnic societies. Three case studies (Nigeria, Lebanon and Bosnia-Herzegovina) determine that rather than external factors, it is the internal structures that make or break the military institution in a socially challenging environment. The book finds that where the political will is present, the multiethnic military can become a symbol of reconciliation and coexistence. Furthermore, it shows that the military as a professional identity can supersede ethnic considerations and thus facilitates cooperation within the armed forces despite a hostile post-conflict setting. In this, the book challenges widespread theories about ethnic identities and puts professional identities on an equal footing with them.