Ethnic democracy is a form of democratic ethnic conflict regulation in deeply divided societies. In The Challenge of Ethnic Democracy, Yoav Peled argues that ethnic democracy is constituted by the combination of two contradictory constitutional principles: liberal democracy and ethno-nationalism, and that its stability depends on the existence of a third, mediating constitutional principle of whatever kind. This central argument is supported by an analysis of the history of three ethnic democracies; Northern Ireland under Unionist rule, where ethnic democracy was stable for almost 50 years (1921-1969), then collapsed; The Second Polish republic (1918-1939), where ethnic democracy was written into the constitution but was never actualised; and Israel within its pre-1967 borders, where ethnic democracy was stable for 35 years (1966-2000) but may now be eroding. This book examines the different trajectories of the case studies, demonstrating that Poland lacked a third, mediating constitutional principle, while Israel and Northern Ireland did have such a principle – civic republicanism in Israel, and populism in Northern Ireland. The collapse of ethnic democracy in Northern Ireland resulted from the weakening of populism, that depended on British monetary subsidies for its implementation, whilst the erosion of ethnic democracy in Israel resulted from the decline of civic republicanism since the onset of economic liberalization in 1985. Dealing with ethnic democracy in a comparative framework, this book will appeal to students, scholars and researchers of Sociology, Political Science and Middle East Studies.