Why did Israel invade Lebanon from 1981-1982?

Answer 1

Several Lebanese militant groups, such as the PLO, began to fire rockets into Northern Israel in 1981 and 1982. Israel finally responded by entering the Lebanese Civil War which was going on concurrently with the aim of removing such militant groups from Lebanon.

Answer 2

Israel has fought with Lebanon on several occasions including: Israel's entrée into the Lebanese Civil War in 1982, the Occupation of South Lebanon from 1982-2000, or the recent Israeli-Hezbollah War in 2006. All three stem from different causes. The primary ones for each are listed below.

1) The Lebanese Civil War had a number of causes separate to Israel and Israel only entered the War midway through. The causes of the Lebanese Civil War included, but were not limited to:

1. The rising percentage of Shiite Muslims and sinking percentage of Maronite Christians and the Shiites wanting more power.
2. The arrival of Palestinian Militant Organizations like the PLO fleeing Jordan after King Hussein's Black September who brought unrest and chaos with them.
3. The languishing, horrible conditions of the vast numbers of Palestinian Refugees in Lebanon.
4. The increasing militancy and radicalization of the Maronite Christian minority.
5. The increasing Syrian support of Shiite Paramilitary Groups

Israel entered the Lebanese Civil War on account of the following two reasons:

1. Palestinian Paramilitary Organizations began to rain rockets down on Northern Israel in an attempt to goad Israel to enter the Lebanese Civil War. The PLO believed that such an entry would unite the Shiites and Sunnis behind one banner to repel the Israelis. The Union did not form, but Israel did retaliate by crossing the border and hunting down the PLO.
2. Christian Falangists, with whom Israel quickly allied, promised Israel a longer term ceasefire and more amicable relations in the future. Israel wanted a chance at peace with Lebanon and therefore supported those who would advocate for this.

2) The Occupation of Southern Lebanon was a result of the Lebanese Civil War. Israeli troops were already in Lebanon and just retreated to positions south of the Litani River, but north of the Israeli-Lebanese border. Hezbollah and other paramilitary groups harassed the Israeli occupying force, leading to minor skirmishes in the area. In 2000, as a sign of restraint, Israeli Prime Minister Ehud Barak withdrew the Israelis to the 1980 borders to the satisfaction of the United Nations, but not to Hezbollah which considers parts of the Israeli-occupied Golan to be Lebanese territory.

3) The Israeli-Hezbollah War began from Hezbollah's gross misinterpretation of how strongly Israel would respond to its illicit activities. The War had a number of causes that included, but were not limited to:

1. Hezbollah kidnapped two Israeli soldiers on the Lebanese border: Regev and Goldwasser, violating the strong Israeli sense that no soldier can be ever left behind. This prompted an Israeli incursion into Lebanon to retrieve the soldiers.
2. Hezbollah, upon seeing the Israeli soldiers, launched Soviet Katyusha Missiles into Israel, causing the Israelis to amp up their incursion to a proper invasion and airstrike.

Answer 3

Israel invaded Lebanon to drive out the Palestine Liberation Organization, which was sending rockets over the border from Lebanon into Israel and attempting to destabilize Israel.

Answer 4

to protect the people living there