When Hamas terrorists invaded southern Israel on Oct. 7, 2023, Ran Gvili, a 24-year-old Israeli police officer on medical leave with a broken shoulder, nonetheless rushed to help. He helped evacuate Nova festival survivors, then fought at Kibbutz Alumim, near the Gaza border, where he fell in battle. His body was taken into Gaza, one of 251 hostages, living and dead. Getting all the hostages back became an obsession for Israelis in the months and years that followed. By this January, Gvili’s body was the final hostage. “There was a lot of pressure to find him in Gaza. We worked,...