The citizenship of children born to US military personnel stationed in the zone was established by Congress many years ago.
As was the lack of automatic citzenship of children born to US teenage mothers who mated with foreigners and gave birth off US soil.
This is no doubt true. However the exact definition of what "natural born citizen" means has never been defined by the Supreme Court. As far as I am concerned it is a non-issue and should be. But, like I said, if all McCain has left is to question something like this, he is pretty much finished.