The reasons behind the rise and expansion of the Islamic State (ISIS) in Iraq (2003-2017)

1980s are remembered for the Soviet Union invasion of Afghanistan and it is also the period when Islamic jihad organizations that act with the most radical Islamic movements like Salafism emerged. In this period, many Salafist groups and organizations declared jihad creating a global front first against Soviet Union then against USA and Western countries. Later on, the Islamic State organization (also known as ISIS) had taken its first steps in 1999 which has later become the most dangerous and outrageous terror organization in the world in recent years with the help of Al-Qaeda's founder Usame Bin Ladin who was the leader of this global front. ISIS believed that there is not a single Muslim State in the world existed and aimed to start a khilafat movement first in Middle East then in the whole world. After 2003 Iraq Invasion, ISIS emerged in the region. In 2011 and in the ongoing period, it managed to establish khilafat after invading a wide area including western regions of Iraq and eastern side of Syria. Besides, ISIS has become a threat that spreads fear not only in the regions it has been ruling, but also in all over the world in terms of manpower, military sufficiency, financial resources and propaganda as a result of its invasions. This study investigates the period between 2003 to 2017, when ISIS established khilafat which was an important period in Iraq's political history and, it analyses the importance of local conditions for the organization's emergence, its gathering such strength and its expansion. In this context, after the information on the organization's structuring process is given, the following issues are discussed; the suspension of Baathists from state institutions and organizations during the instability after the USA invasion of Iraq ended Saddam Regime in 2003, Sectarian violence between 2006-2007, suspension of Sunnis from political process, ISIS's rising and spread in Iraq and Syria taking advantage of the absence of power and authority in 2011, and the role of the Baathist officers in the organization's managerial positions. Keywords: ISIS, Islamic State, Iraq, Syria, Sect, Sectarian Violence, Terror, Terrorism.