The moral obligation to kill ‘occupiers’ of Muslim land has to end. This ‘authentic’ law is closely tied to another ‘authentic’ law: The penalty for leaving Islam is death. Islam is a one way street. Once you become Muslim, you cannot go back. Once land is controlled by Islam, it can never become non-Muslim. (In the eyes of Islam.) Once another entity ‘occupies’ it, then a moral obligation to kill the ‘occupiers’ is triggered. This is closely tied in with Jihad. As Bernard Lewis points out: "For most of the fourteen hundred years of Muslim history, Jihad has been commonly interpreted to mean armed struggle for the advancement or defense of Muslim power." If the means for open warfare is not available, irregular warfare is the natural result. It is not a far step to take to become what we consider to be a ‘terrorist’.
These issues can be seen to be important influencing factors in the many Arab-Israeli wars. Unless Islam is expanding, wars will be common. On top of this, once enough people disagree in a significant way about the interpretation of an ‘authentic’ law, the rest of Islam sees them as having left the faith. They have become Apostates. The penalty is death, along with the loss of property (booty) that is the reward for the warriors who enforce the law. No wonder warfare is so common in the areas where Islam is influential.
These issues not only trigger violence and warfare, but also can been seen to be impossible to eliminate without violence and warfare. These issues are combining with the general repressive nature of Islamic law and contributing as to why so much of the Muslim world has such anger management problems.