Abstract: The Islamic State of Iraq and Syria/the Levant (ISIS/ISIL) has threatened human and national security of Iraq and Syria as well as the rest of the worldas its influence spreads in forms of terrorism in many parts in the world such as Yemen, Libya, Sinai, Mali, Somalia, North-Eastern Nigeria, Pakistan and some parts of Southeast Asia and Europe. USA has called for a formation of a new international coalition to confront ISIS in Iraq to provide a support for the Iraqi government institutions to impose the sovereignty of law and to provide equal opportunities for the members in federal governmental institutions. Following the declaration from the US President, an international coalition was formed by the USA, British, Bahrain, Jordan and Iraq on 10th September 2014, in addition to the military and humanitarian supports provided by NATO and EU states. A number of international organizations namely the UN and NATO as well as regional organizations namely the Arab League and EU have moved to contain the development of ISIS but the results were limited and inconclusive. Using neoliberal institutionalist perspective, the study argues that an effective international organization is required to solve the crisis caused by ISIS in Iraq and the shortcoming in solving ISIS crisis is caused by the non-existence of a unitary international organization. The study firstly identifies the current operating role of those international and regional organizations in response to ISIS in responding and preventing ISIS and its expansion. Secondly, the reasons behind the shortcoming of the current international coalition are discussed. Consequently, the study suggests the formation of a stronger international organization that manages the strategy to fight IS in Iraq.