Though it took the form of an Israeli military incursion into Southern Lebanon, Operation Litani arose from the long-running Israeli–Palestinian conflict. After 1968, the PLO, Popular Front for the Liberation of Palestine, and other Palestinian groups established a quasi-state in southern Lebanon, using it as a base for raids on civilian targets in northern Israel, as well as terror attacks on Israeli and other targets worldwide. This was exacerbated by an influx of 3,000 PLO militants fleeing a defeat in the Jordanian civil war and regrouping in southern Lebanon. Israel responded with damaging attacks against PLO bases.