"Israel 1982 Invasion of Lebanon", The Library of Congress Country Studies; CIA World Factbook via Photius Coutsoukis. "Since 1970, Israeli settlements near the southern border of Lebanon had been exposed to harassing attacks from forces of the Palestine Liberation Organization (PLO), which had been driven out of Jordan. On three occasions, in 1970, 1972, and 1978, Israel had retaliated by ground operations carried out up to Lebanon's Litani River. ... Meanwhile Israel had conducted preemptive shelling and air strikes to deter PLO terrorist attacks on settlements in Galilee in northern Israel."
Time (2006). The Year in Review. New York: Time Books. ISSN1097-5721. "For decades now, Arab terrorists operating out of southern Lebanon have staged raids and fired mortar shells into northern Israel, denying the Israelis peace of mind. In the early 1980s, the terrorists operating out of Lebanon were controlled by Yasser Arafat's Palestine Liberation Organization (P.L.O.). After Israel's ambassador to Britain, Shlomo Argov, was shot in cold blood and seriously wounded by the Palestinian terror group Abu Nidal in London in 1982, fed-up Israelis sent tanks and troops rolling into Lebanon to disperse the guerrillas." (pp. 44–45)
