The modern Islamic terrorist movement is largely rooted in the collapse of the Ottoman Empire and the subsequent removal of the Caliph, the Islamic political-religious leader, in 1924. After the collapse of the Ottoman Empire, the more secular and progressive Republic of Turkey came into existence, seeking many modern social and economic reforms. This marked the beginning of a secularization and modernization period for the region as a whole.
The event resonated throughout the Islamic community as the Ottoman Caliph was the strongest entity in Islam at that time. In the vacuum of Islamic central authority that followed, the Muslim Brotherhood grew into formation. This type of formation, a fundamentalist reaction, is common during all times of rapid progress throughout the world and is caused by traditionalists attempting to resist change.
Simultaneously, Western powers, mainly the French and British, were exerting control over large sections of the Middle East after WWI. Many of the arbitrary borders they established split ethnic groups into incoherently formed states with deep social and ethnic divides. Those borders largely remained after Middle Eastern states gained their independence from European power.
This factor has helped stir tensions in the region ever since, and has been a challenge to creating functional states. To the dismay of traditionalists, the formation of Turkey and the later independence of Western colonial Middle-Eastern states ushered in a new era of relative secularism. Nationalism became a replacement for common religious identity within the state, though religion is mostly always present in Middle Eastern politics.
The Muslim Brotherhood took a relatively median political position during that timeframe, seeking to fuse Islamic tradition with the nationalist agenda as a means to limit societal change. Following a crackdown in 1954 after a failed assassination attempt on Egypt’s al-Nasser, the Brotherhood was abolished as a legitimate political movement in Egypt and went underground. As is typical of outlawed political movements and parties, when the movement is pushed underground and access to legitimate means of political influence is removed, the group’s ideology becomes more extreme and they resort to unconventional methods of influence.