Kill the ‘occupiers’ of Muslim land.
An example: The Catholic Church owns the land that a church in Chicago has been built on. If any group of armed people took it over; Catholics from Illinois, Mississippi, Brazil or Canada do NOT go in and take them out. The U.S. government sends in the army, or National Guard or SWAT team or whatever. Islam has a long history of this type of action. As has been seen so often today, Islam still retains a sizable number of followers who believe that Islam overrides the modern national government. If the means for open warfare is not available, irregular warfare is the natural result. It is only the next step to become what we consider to be a ‘terrorist’.
A religion like Islam does not have ‘land’ nor ‘waters’ to defend. The following statement was declared by Imams that met in Istanbul in March 2008 is a classic example: "The obligation of the Islamic Nation [is] to regard the sending of foreign warships into Muslim waters, claiming to control the borders and prevent the smuggling of arms to Gaza, as a declaration of war, a new occupation, sinful aggression, and a clear violation of the sovereignty of the Nation. This must be rejected and fought by all means and ways."
Please note the use of the terms "Islamic Nation and "Muslim waters" and "Sovereignty of the nation". These concepts are common throughout the Islamic world and contribute greatly to the warfare that is common where Islam is in contact with the nation-states of the world.
As can be seen, this concept is one of the basic causes of the continuing Arab-Israeli conflict. All of Israel is sitting on ‘occupied’ land. Two additional parts of this issue I would like to discuss.
1) Once land becomes Islamic controlled, it can never revert back to anything else because it is considered to be ‘occupied’. (This is tied in with reason #3, the penalty for leaving Islam is death)
2) This would be comparable to Native Americans launching attacks upon the rest of the population because all of the land that the United States sits on would be considered ‘occupied’.
This is only one the major issues present within Islam that invites open warfare.