WHAT PROMPTED HAMAS' ATTACK ON ISRAEL?

As Israel-Hamas war enters seventh day, here is what we know so far

Key questions answered : WHAT IS THE SITUATION IN GAZA? WILL ISRAEL LAUNCH A GROUND ASSAULT? WHAT ARE THE CHANCES THAT THE WAR WILL SPREAD? WHAT HAS BEEN THE RESPONSE FROM THE U.S. AND OTHER NATIONS? WHAT PROMPTED HAMAS' ATTACK ON ISRAEL?