JihadJihad linguistically means "effort" or "striving" in Arabic. It is considered a fundamental principle of Islamic faith, and is sometimes called "The sixth pillar of Islam", in reference to the Five Pillars of Islam. The two meanings of Jihad are: 1. A personal, internal struggle (inner or greater Jihad) 2. An external battle or war against aggressors (outer or lesser Jihad) Inner Jihad is not a controversial issue among Muslims, but outer Jihad is. In one quote about Jihad, the Qur'an says: "To those against whom war is made, permission is given (to defend themselves), because they are wronged - and verily, Allah is Most Powerful to give them victory - (they are) those who have been expelled from their homes in defiance of right - (for no cause) except that they say, 'Our Lord is Allah'..." (22:39-40) Many modern Arab acts of terrorism have been considered an expression of jihad. Two Islamist organizations call themselves "Islamic Jihad": Egyptian Islamic Jihad and Palestinian Islamic Jihad. These groups are considered mainstream by millions of supporters within the Islamic world, who see a strong religious justification for a military understanding of the term jihad. For militant groups within the Islamic cultural sphere, a person who commits suicide as a part of struggle against oppression is considered a shahid - holy martyr - and is held to have earned a place in heaven. Many Muslims disagree with this view, however, saying that even in such circumstances, suicide remains a sin. Jihad as a war against non-Muslims "Jihad has been decreed to repel aggression and to remove obstructions impeding the propagation of Islam in non-Islamic countries." As Lt. Col. M. M. Qureshi points out in his "Landmarks of Jihad", "only a war which has an ultimate religious purpose can be termed as jihad." (Shayk Muhammad Abu Zahra, Egyptian member of the Academy of Islamic Research). There is nothing historically unique about this position, although such clear (and popular) advocacy of forced proselytization may now be relatively uncommon. See also the "Reputation and evaluation" section of Crusade for a discussion of how the terms "Crusade" and "Jihad" are perceived differently in the West and the Islamic world. Many analysts hold that the severe economic and governmental differences between the Islamic world and the rest of the world contribute to fueling this notion of jihad.