Sabra and Shatila massacre
Israel steps into the conflict in 1982 by sending troops to Lebanon. This action follows the murdering attempt on Shlomo Argov, the Israeli ambassador. It gives to Israel the pretext to invade the south of Lebanon and the capital. This operation is called "Peace for Galilee". Its goal behind the intervention was to drive out the PLO fighters who established in the country. Though the murdering attempt on Shlomo Argov was not perpetuated by the PLO, it gave to Israel the justification to attack Palestinian fighters in Lebanon. The Israeli army slowly advance until Beirut where they join their military forces with the Syrian forces already involved in the conflict and with the Lebanese Phalanges. They will not enter the capital, though, after a cease-fire agreement was conclude with the USA in September.