The Crusades- Share your view

• Missionary religions, seeking conversion of others
• Universal, "all-or-nothing" religions, in the sense that it is believed by both sides that only their faith is the correct one
• Teleological religions, that is, that their values and beliefs represent the goals of existence and purpose in human existence.

More recent factors contributing to a Western-Islamic clash, Huntington wrote, are the Islamic Resurgence and demographic explosion in Islam, coupled with the values of Western universalism - that is, the view that all civilizations should adopt Western values - that infuriate Islamic fundamentalists.

All these historical and modern factors combined, Huntington wrote briefly in his Foreign Affairs article and in much more detail in his 1996 book, would lead to a bloody clash between the Islamic and Western civilizations. Along with Sinic-Western conflict, he believed, the Western-Islamic clash would represent the bloodiest conflicts of the early 21st century. Thus, the September 11, 2001 terrorist attacks and subsequent events including the Afghanistan and Iraq wars have been widely viewed as a vindication of the Clash theory.^{[citation needed]}

 Core state and fault line conflicts

In Huntington's view, intercivilizational conflict manifests itself in two forms: fault line conflicts and core state conflicts.

Fault line conflicts are on a local level and occur between adjacent states belonging to different civilizations or within states that are home to populations from different civilizations.

Core state conflicts are on a global level between the major states of different civilizations. Core state conflicts can arise out of fault line conflicts when core states become involved.^[6]

These conflicts may result from a number of causes, such as: relative influence or power (military or economic), discrimination against people from a different civilization, intervention to protect kinsmen in a different civilization, or different values and culture, particularly when one civilization attempts to impose its values on people of a different civilization.