Syria is much less safe than Israel is, but millions of people live there, and newswires can buy information from them; that's what a stringer is. The allegations I've read are that, on a good day in 2018, AP might have had one stringer to get information from. That's a decision AP made, not a reality it had to conform to.
https://en.wikipedia.org/wiki/List_of_journalists_killed_dur...