Yea you have to be a Jewish athlete to compete in the Maccabiah games but there's exceptions sometimes like some Arab Israelis have competed in it before. It's held in Israel every four years. It's an athletic event similair to the olympics which is where the nickname jewish olympics was coined from. There's something around 40 sports events with something around 55 countries participating. Every Israeli citizen and every Jewish person not an Israeli citizen, is eligible to compete in the Games.