FUNCTION: Established to confirm the withdrawal of Israeli forces from southern Lebanon, to restore international peace and security and to assist the Government of Lebanon in ensuring the return of its effective authority in the area.

BACKGROUND:
In the early 1970s, tension along the Israel Lebanon border increased, especially after the relocation of Palestinian armed elements from Jordan to Lebanon. Palestinian commando operations against Israel and Israeli reprisals against Palestinian bases in Lebanon intensified.

On 11 March 1978, a commando attack in Israel resulted in many dead and wounded among the Israeli population; the Palestine Liberation Organization (PLO) claimed responsibility for that raid. In response, Israeli forces invaded Lebanon on the night of 14/15 March, and in a few days occupied the entire southern part of the country except for the city of Tyre and its surrounding area.

On 15 March 1978, the Lebanese Government submitted a strong protest to the Security Council against the Israeli invasion, stating that it had no connection with the Palestinian commando operation. On 19 March, the Security Council adopted resolutions 425 (1978) and 426 (1978), in which it called upon Israel immediately to cease its military action and withdraw its forces from all Lebanese territory. It also decided on the immediate establishment of UNIFIL. The first UNIFIL troops arrived in the area on 23 March 1978.

In June 1982, Israel invaded Lebanon again. For three years, UNIFIL remained behind the Israeli lines, with its role limited to providing protection and humanitarian assistance to the local population to the extent possible. In 1985, Israel carried out a partial withdrawal, but it retained control of an area in southern Lebanon manned by the Israel Defense Forces (IDF) and by Lebanese de facto forces (DFF), the so called "South Lebanon Army.