I think it's pretty difficult to assess what someones true motives are in wanting to join up. Particularly when you are dealing with the type of animosity that exists between jews and arabs. If you are relying on their translations of materials that has the potential to effect mid-east policies, you want to ensure that you are not receiving colored copy.
For that reason it seems far more risky to hire Arabs than Jews. The Jews haven't attacked us ever. I'm sure the Jews see more reason for the survival of the USA.