@Cristina While I agree that Nidal Hasan should definitely have been caught and dealt with long before this occurred, since he was known to the FBI, but as far as I know, his transition to radicalism happened while he was in the service; what you are suggesting about recruiting practices goes beyond discriminating against religious groups to only being concerned with last names. So if we were to have an army recruit with the last name Princip, you would, out of fear for his radical ideas about how Austro-Hungary should be governed, demand that he not be allowed to be in the military?
Or are you just saying that anyone with a last name that seems middle-eastern should be viewed with a careful eye, and have limited choices for employment and enfranchisement? Because I’m sure that would make the whole population of people with such surnames very pleased. Certain to gain allies that way.