The Palestine Liberation Organization (PLO) is the representative group of the people of Palestine, formed in 1964 by Yasser Arafat. Until 1993, it used violence and terrorism to fight against Israel in irregular warfare, which included rocket attacks, cross-border raids, aircraft hijackings, and massacres, with the 1972 Munich Massacre being one of its most famous attacks. The Israel Defense Forces (IDF) carried out an invasion of Lebanon in 1982 to flush out the PLO from South Lebanon following their launching of Katyusha rockets at northern Israel, and the PLO was besieged in their Beirut stronghold by Israel. The PLO was not only fought against by Israel, but also by Jordan in the "Black September in Jordan" war in 1970, where the Jordanian Army fought against the Palestinian fedayeen guerrillas. After the Oslo Accords in 1993, the group recognized Israel's right to exist in peace, and Israel recognized the PLO as the group that represented the Palestinian people. However, Arafat was believed to have instigated the Second Intifada in 2000-2005, and his successor Mahmoud Abbas was alleged to have incited more violence in the Silent Intifada and the Knife Intifada.