The crisis began on 20 December when Elias Hannouche, a former Tiger commander backed by Syria, seized the old National Liberal office in Zahle. After an ambush inside the town killed five Syrian soldiers on 22 December, Syrian artillery opened fire on it (Ménargues; Hanf counts an officer and five soldiers). De Clerck and Malsagne date the bombardment to 21 December and call it the first round of the battle of Zahle. Most of the former Tigers then joined the Lebanese Forces, and Syrian troops stayed positioned around the town until the siege of spring 1981.

De Clerck and Malsagne count the murder of Dany Chamoun, his wife and two of their children as the last act of violence between Christian factions. The place is given as Baabda (Confluences) or 'his east Beirut home' (Fisk). Chamoun had backed Aoun, though critically, and was opposed to Syria's presence. Hanf notes that many blamed Syria, but judges that killing a whole family suggests a militia vendetta; Fisk likens it to the Phalangists' earlier killing of Tony Frangieh, his wife and baby. Samir Geagea was later tried for the murder (Picard).