Trust the Muslim one who fled to Lebanon - twice? Or the officers that let him flee the second time?
Or if you want to go back a little, here's a list of some of the Marines who spied against the US.
http://www.dss.mil/training/espionage/Marines.htm
Folks from 1985, 1989, 1991, 1982.
Remember the secret service guy who caused a stir on an airplane because he wanted to bring his gun on the plane. He also had muslim literature on his person.