Maybe it's difficult to prove that these people have travelled overseas to fight for a foreign power.

But if they have, and I include those who have gone overeas to fight for Israel, then they have demonstrated support and loyalty for another and a foreign regime and that, I believe should be grounds for consideration that their Australian citizenship be revoked, even if they were born here.

It's a legal thing. Maybe the law needs to be changed in order to prevent the return of those who have been proved  to have  taken up arms to fight for a foreign power.

Let them go . . . but prevent their return. We as a country cannot lose much by this deal. They, as wannabe fighters for a foreign cause are indulged as being free to do as they please. Win - win situation.

If they survive and find themselves as stateless individuals afterwards well, they choose that condition freely.