Thousands of Jewish athletes from 50 countries will compete in the 18th Maccabiah Games in July. The event, sometimes referred to as the "Jewish Olympics," is held every four years. Worries that it represents a high-profile target for Palestinian militants seeking vengeance for Israel's destruction in Gaza, could decide some athletes against traveling to Israel. Athletes have been targets in the past, notably in 1972, when Palestinian militants killed 11 Israeli athletes at the Munich Olympics.