Christian militia army financed and trained by Israel with a view to control the Israeli security zone in the South of Lebanon.

The beginning of the civil war in 1975-76 was a decisive turning point. Israel intervened directly with the Christian forces under the command of Major Sa'ad Haddad following the break-up of the Lebanese army in 1976.

In March 1978, the Israeli invasion of the South of Lebanon lasted three months. It was not until June and only following strong pressure that Israeli withdrawal was followed by the deployment of UNIFIL, except on a strip of land of 100 km long and 8 to 20 km wide from Maqoura on the Mediterranean coast along the border with Israel up to Mount Hermon and the Litani River. This enclave with a population of 100,000 (60% Shiite Muslims and 35% Christians) was placed under the leadership of Major Haddad and his 2,000 militia men, strongly backed by Israeli advisors. In May 1980 Haddad's militia became known as the "South Lebanon Army" (SLA). In January 1984, Antoine Lahad replaced Saad Haddad.

Israeli and SLA forces have co-operated ever since in combatting Hezbollah. The SLA (whose present strength is estimated between 5,000 and 10,000 soldiers) advocate for a pro-Western Lebanon and devoid of Syrian presence. Israel demands that the SLA be re-incorporated into the regular Lebanese Army as a precondition for making peace with Lebanon while the Lebanese government sees the SLA militiamen as traitors.

In June 1999, after the election of Ehud Barak as Prime Minister of Israel, the SLA started withdrawing from the northernmost part of the so-called "Security Zone", the Jezzine area of which it took control in 1985.