SYDNEY -- Australian leaders promised Monday to immediately overhaul already-tough gun control laws after a mass shooting targeted a Hanukkah celebration on Sydney's Bondi Beach. At least 15 people died in the attack, which has fueled criticism that authorities are not doing enough to combat a surge in antisemitic crimes. Among the new measures proposed would be a limit on the number of guns someone can own and a review of licenses held over time. Those and other actions would represent a significant update to the landmark national firearms agreement, which virtually banned rapid-fire rifles after a gunman killed 35...