Fighting among rival Palestinian and Arab movements has played a crucial role in shaping Israel's security policy towards Palestinian militants, as well as in the Palestinian leadership's own policies. As early as the 1930s revolts in Palestine, Arab forces fought each other while also skirmishing with Zionist and British forces, and internal conflicts continue to the present day. During the Lebanese Civil War, Palestinian baathists broke from the Palestine Liberation Organization and allied with the Shia Amal Movement, fighting a bloody civil war that killed thousands of Palestinians.