Crossing into Lebanon to destroy PLO started as a successful mission, and when the IDF destroyed the Syrian SAM belt in the Bekaa Valley through Operation Mole Cricket 19 it looked like victory was assured. Nonetheless as Defense Minister Ariel Sharon pursued Yasser Arafat of the PLO (and his dreams of a peace treaty) into the Siege of Beirut, he discovered that his Maronite allies were not to be trusted and that it is easier to enter Lebanon than to leave.