Afaf al-Najar had found a way out of Gaza. The 19-year-old won a scholarship to study communications in Turkey, secured all the travel documents and even paid $500 to skip the long lines at the Rafah crossing with Egypt. But she failed to do so because of a male guardian ship law enacted by the militant group Hamas, which rules the territory. The law says that a male relative can petition a court to prevent a woman from travelling if it would result in “absolute harm.” Al-Najar’s father filed a petition, and the court prevented her from travelling so that...