The governments, secret services and other organizations do a lot of work and there are a lot of programs. Here is the background to all this.
Turkey is a member of NATO. I know that every secret service in the western world and beyond, and NATO are at the border. On the other hand, the jihadists are not parachuted in. They come from somewhere. There are so many programs, things that are left unsaid, and secrets.
Turkey has a lot more choice than Chad or Mali, that have no ways of monitoring their borders. There are a lot more choices in this case.