How did the Palestine Liberation Organization become involved in the Lebanese Civil War?

Following the Palestine Liberation Organization (PLO)’s expulsion from Jordan in 1971, the organization relocated its primary bases to Lebanon to continue its armed struggle against Israel. This move placed the PLO in a precarious position within Lebanon’s complex sectarian landscape.12

The PLO’s involvement in the Lebanese Civil War was driven by several factors:

• Sectarian Tensions: The presence of a large Palestinian population and armed guerrilla groups exacerbated existing divisions between Lebanon’s Muslim and Christian communities.34
• Escalating Conflict: While the PLO initially attempted to remain neutral, by late 1975, various factions within the organization—particularly those in the "rejection front"—formed alliances with Lebanese leftist and Muslim groups fighting against Christian militias.3
• Cycle of Violence: The war is often dated to April 1975, when Phalangist forces attacked a bus carrying Palestinians, triggering a broader conflict. As fighting intensified, the PLO became deeply embroiled in the sectarian disputes, contributing to the country's destabilization.513

Ultimately, the PLO’s presence and its participation in the fighting proved disastrous for the organization and the Palestinian population in Lebanon, leading to significant casualties and eventual military pressure from both Christian militias and Israeli forces.3