South Lebanon conflict (1985–2000) in the context of "South Lebanon Army"

The Israeli occupation of Southern Lebanon lasted for eighteen years, from 1982 until 2000. In June 1982, Israel invaded Lebanon in response to attacks from southern Lebanon by Palestinian militants. The Israel Defense Forces (IDF) occupied the southern half of Lebanon as far as the capital city Beirut, together with allied Maronite Christian paramilitaries involved in the Lebanese Civil War. The IDF left Beirut on 29 September 1982, but continued to occupy the country's southern half. Amid rising casualties from guerrilla attacks, the IDF withdrew south to the Awali river on 3 September 1983.

From February to April 1985, the IDF carried out a phased withdrawal to a "Security Zone" along the border, which it said was to protect northern Israel. From this point onwards, Israel supported the South Lebanon Army (SLA), the Lebanese Christian paramilitary, against Hezbollah and other Muslim militants. They fought a guerrilla war in Southern Lebanon throughout the occupation.

The United Nations Interim Force in Lebanon (Arabic: قوة الأمم المتحدة المؤقتة في لبنان; Hebrew: כוח האו"ם הזמני בלבנון), or UNIFIL (Arabic: يونيفيل; Hebrew: יוניפי״ל) is a United Nations peacekeeping mission established on 19 March 1978 by United Nations Security Council Resolutions 425 and 426, and several further resolutions in 2006 to confirm Hezbollah demilitarisation, support Lebanese army operations against insurgents and weapon smuggling, and confirming Israeli withdrawal from Lebanon, in order to ensure that the government of Lebanon would restore its effective authority in the area. The 1978 South Lebanon conflict came in the context of Palestinian insurgency in South Lebanon and the Lebanese Civil War.

The mandate had to be adjusted due to the Israeli invasion of Lebanon in 1982 and after the Israeli withdrawal from Lebanon in 2000. Following the 2006 Lebanon War, the United Nations Security Council enhanced UNIFIL and added additional tasks to the mandate such as aiding displaced persons.

The Israeli–Lebanese conflict, or the South Lebanon conflict, is a long-running conflict involving Israel, Lebanon-based paramilitary groups, and sometimes Syria. The conflict peaked during the Lebanese Civil War. In response to Palestinian attacks from Lebanon, Israel invaded the country in 1978 and again in 1982. After this it occupied southern Lebanon until 2000, while fighting a guerrilla conflict against Shia paramilitaries. After Israel's withdrawal, Hezbollah attacks sparked the 2006 Lebanon War. A new period of conflict began in 2023, leading to the 2024 Israeli invasion of Lebanon.

The Palestine Liberation Organization (PLO) recruited militants in Lebanon from among the Palestinian refugees who had been expelled or fled after the creation of Israel in 1948. After the PLO leadership and its Fatah brigade were expelled from Jordan in 1970–71 for fomenting a revolt, they entered southern Lebanon, resulting in an increase of internal and cross-border violence. Meanwhile, demographic tensions over the Lebanese National Pact led to the Lebanese Civil War (1975–1990). PLO actions were one of the key factors in the eruption of the Lebanese Civil War and its bitter battles with Lebanese factions caused foreign intervention. Israel's 1978 invasion of Lebanon pushed the PLO north of the Litani River, but the PLO continued their campaign against Israel. This invasion led to the deployment of United Nations peacekeepers in southern Lebanon. Israel invaded Lebanon again in 1982 and, in alliance with the Christian Lebanese Forces, forcibly expelled the PLO. In 1983, Israel and Lebanon signed the May 17 Agreement providing a framework for the establishment of normal bilateral relations between the two countries, but relations were disrupted with takeover of Shia and Druze militias in early 1984. Israel withdrew from most of Lebanon in 1985, but kept control of a 19-kilometre (12-mile) security buffer zone, held with the aid of proxy militants in the South Lebanon Army (SLA).