I'm sure that is a significant motivating factor. But our military will not dare admit it for fear of angering the very people who would kill us anyways.
Major Hassan at Ft. Hood is an example of avoiding the reality of fundamental Islam. His shooting of our troops was described as an example of "workplace violence".
Somewhere along the line a religious person has to decide whether to serve his God or to serve man.
If a person is a Christian it does not pose much of a problem for anyone that comes in contact with them.
If the person is a Muslim it is a problem for anyone who is not a Muslim. -tom