PARIS (AP) — When three British schoolgirls trundled across the Syrian border; when a pregnant 14-year-old ran away from her Alpine home for the second time; when a sheltered girl from the south of France booked her first trip abroad — they were going to a place of no return. Only two of the approximately 600 Western girls and young women who have joined extremists in Syria are known to have made it out of the war zone.