The question of majorities and minorities has dominated the Iraqi political scene since the American-led invasion of 2003. As an occupying power, the US enshrined sectarianism in post-Saddam Iraq through divisive policies and structures that continue to pervade the political institution from top to bottom. As a result, what was considered a remedy for Iraq's political ills opened the gates for more sectarian division, the dispersion of religious minorities and power struggles between the main majority groups: Shia Arabs, Sunni Arabs and Kurds. How this deadlock will be resolved is the key question that Iraq is facing as it prepares for an imminent defeat of the so-called Islamic State (Da'sh or ISIS). This paper traces the development of the concepts of majorities and minorities in Iraq's recent history, analyzing the factors that led to the sectarian paralysis of today and exploring possibilities for a post-ISIS political solution that preserves the multi-ethnic, multi-religious character of the Iraqi nation-state.