The South Lebanon conflict, lasting from 1985 to 2000, involved Israel and the South Lebanon Army (SLA), a Catholic Christian-dominated force, against primarily Hezbollah-led Shia Muslim and left-wing guerrillas in the Israeli-occupied "Security Zone" in southern Lebanon.^[214] The SLA received military and logistical support from the Israel Defense Forces and operated under an Israeli-backed provisional administration. This conflict was an extension of the ongoing strife in the region, including the Palestinian insurgency in South Lebanon and the broader Lebanese Civil War (1975–1990), which saw conflicts between various Lebanese factions, the Maronite-led Lebanese Front, the Shia Amal Movement, and the Palestine Liberation Organization (PLO).

Before the 1982 Israeli invasion, Israel aimed to eliminate PLO bases in Lebanon, supporting Maronite militias during the Lebanese Civil War. The 1982 invasion led to the PLO's departure from Lebanon and the establishment of the Security Zone by Israel to protect its civilians from cross-border attacks. However, this resulted in hardships for Lebanese civilians and Palestinians. Despite partially withdrawing in 1985, Israel's actions intensified conflicts with local militias, leading to the rise of Hezbollah and the Amal Movement as significant guerilla forces in the Shia-majority south. Over time, Hezbollah, with support from Iran and Syria, became the predominant military power in southern Lebanon.

The nature of warfare conducted by Hezbollah, including rocket attacks on the Galilee and psychological tactics, challenged the Israeli military.^[215] This led to growing public opposition in Israel, particularly after the 1997 Israeli helicopter disaster. The Four Mothers movement became instrumental in swaying public opinion towards withdrawal from Lebanon.^[216]

Although the Israeli government hoped for a withdrawal as part of a broader agreement with Syria and Lebanon, negotiations failed. In 2000, following his election promise, Prime Minister Ehud Barak unilaterally withdrew Israeli forces in accordance with United Nations Security Council Resolution 425 of 1978. This withdrawal led to the collapse of the SLA, with many members fleeing to Israel.^[217] Lebanon and Hezbollah still view the withdrawal as incomplete due to Israel's presence in Shebaa Farms. In 2020, Israel officially recognized the conflict as a full-scale war.^[218]