By the mid-1970s, Arafat and his Fatah movement found themselves in a tenuous position. Arafat increasingly called for diplomacy, perhaps best symbolized by his Ten Point Program and his support for a UN Security Council resolution proposed in 1976 calling for a two-state settlement on the pre-1967 borders. But the Rejectionist Front denounced the calls for diplomacy, and a diplomatic solution was vetoed by the United States. In 1975, the increasing tensions between Palestinian militants and Christian militias exploded into the Lebanese Civil War, involving all factions. On 20 January 1976, the PLO took part in the Damour massacre in retaliation to the Karantina massacre. The PLO and Lebanese National Movement attacked the Christian town of Damour, killing 684 civilians and forcing the remainder of the town's population to flee. In 1976 Syria joined the war by invading Lebanon, beginning the 29‑year Syrian occupation of Lebanon, and in 1978 Israel invaded South Lebanon in response to the Coastal Road Massacre, executed by Palestinian militants based in Lebanon.