When riots erupted over the reconstruction of the Ferhadija Mosque in Banja Luka in May 2001 and at the same time the dominant Croat party, the Croatian Democratic Community (HDZ), continued its policy of boycotting Bosnian institutions, it seemed as if the fragile interethnic peace, established by the Dayton Peace Accord (DPA) of November 1995, might disintegrate. In reality, these crises merely re ect the continuing dominance of ethnicity in post-war Bosnia. These events can also be viewed as a response of nationalist political parties to a recent trend away from ethnic separation and suspicion to a more integrated Bosnia. A key decision by the Constitutional Court and the establishment of new governments at the level of entities and joint institutions without nationalist parties for the rst time since 1990 seem to point towards a more multinational Bosnia. Throughout the past decade, Bosnia has experienced broad range of interethnic relations, from peace and co-existence to war and separation. After the brief unsuccessful attempt of power-sharing from 1990/1991, the reminder of the rst half of the decade was shaped by attempts to dismantle power-sharing structures and destroy co-existence through mass murder, expulsions and separation. The years following the Dayton Peace Accords (DPA) have brought peace, but only limited success in fundamentally improving interethnic relations and establishing a functioning system of joint decision-making between the three predominant national groups of the country. The current institutional structure of Bosnia draws from a variety of different institutions and systems of power-sharing. It includes elements from pre-war institutions (such as the collective Presidency), incorporates layers of governance that emerged during the war (such as the two entities), and borrows from other cases and theoretical models of power-sharing. As a consequence, the argument can be made that the system of power-sharing in Bosnia does not constitute any new type of arranging interethnic relations. This paper will argue, however, that the novelty of post-Dayton Bosnia lies in the complexity of the existing institutional structure regulating interethnic relations. The complexity is conditioned both by the multiple layers of governance instituted by the Dayton Peace Accords and also the additional network of international organizations directly engaged—be it in an ad hoc or an institutionalized form—in the administration and decision-making process in Bosnia.