They didn’t get security clearances with their dual citizenship. I know for a fact we don’t do that now.
My service was way back 1980 - 1986, as a linguist in NAVSECGRU.
The Syrian was in the Air Force and his entire family, Christians, had been slaughtered with he the only survivor. He came here as a child to live with relatives. No family was left in Syria.
The other three were all Jewish with US/Israeli dual citizendships.