The United Nations Interim Force in Lebanon deployed into South Lebanon in the wake of the March 1978 Israeli invasion of Lebanon. By the summer of 1978, UNIFIL had reached a strength of 6,100 troops drawn from 11 countries. It was tasked under UN Security Council Resolution 425 (19 March 1978) with “confirming the withdrawal of Israeli forces, restoring international peace and security and assisting the government of Lebanon in ensuring the return of its effective authority in the area”. Although Israeli forces formally departed Lebanese territory by June 13, 1978, the area was handed over to Israel’s Lebanese ally – the Army of Free Lebanon (late known as the South Lebanon Army) and UNIFIL was denied access to the border. For the next four years, UNIFIL occupied a buffer zone between the Israeli/SLA zone to the south and the stronghold of the Palestinian Liberation Organization to the north.

The PLO were driven out of South Lebanon in Israel’s 1982 invasion of Lebanon. Israel withdrew in 1985 to a border zone, and for the next 15 years was subject to an intensifying campaign of resistance by Lebanese groups, notably Hizbullah. Lack of international will prevented UNIFIL from fulfilling its mandate, but it provided valuable humanitarian services to the local population of the war-torn South.

Following the Israeli troop withdrawal from South Lebanon in May 2000, UNIFIL deployed along the border with Israel – known by the UN as the Blue Line – for the first time, and two years later its strength had declined from 5,600 to 2,000 troops. The July war in 2006 gave a new lease of life to a mission that had been gradually winding down. UNSCR 1701 called for a force of up to 15,000 troops to oversee the ceasefire between Hizbullah and Israel. Its area of operations was expanded to cover the territory between the Litani river and the border with Israel.

As of early March 2007, UNIFIL was comprised of some 12,000 troops drawn from 28 countries, including for the first time a maritime component headed by Germany.