Ever since the 1970s, the world has been confronted with the phenomenon of Islamist terrorism. In the 1990s, the radical Islamist organization AlQaeda perpetrated several destructive and primarily suicidal attacks on American targets. The climax of AlQaeda's terrorism was the September 11, 2001 attack, which was carried out on American soil. After the USled invasion of Iraq in 2003, even more destructive terrorist attacks were started being perpetrated in Iraq by the radical Islamist organization Islamic State. Between 2015 and 2017, the Islamic State carried out several attacks in Western Europe and the United States of America, with the majority of victims being civilians. In the West, the terrorism of AlQaeda and the Islamic State is primarily explained by discussing their irrational destructive nature or their expansionist motives. This should come as no surprise as the West has a long history of antiIslam discourse. However, one should explain Islamist terrorism by taking into account the historical background (the Crusades and the period of European colonialism), the specific grievances of the greater part of the world's Muslim population, and the effects of aggressive Western policies in the Muslim world. In addition, the SunniShia division within Islam must also be accounted for. To achieve this, one can enlist the help of the sociological (religiological) concepts of cultural defense, religious performance and cosmic war.
