The Israel Defense Forces launch Operation Litani, a seven-day campaign to invade and occupy southern Lebanon.

The Israel Defense Forces, alternatively referred to by the Hebrew-language acronym Tzahal (צה״ל), is the national military of the State of Israel. It consists of three service branches: the Israeli Ground Forces, the Israeli Air Force, and the Israeli Navy. It is the sole military wing of the Israeli security apparatus. The IDF is headed by the chief of the general staff, who is subordinate to the defense minister.

The 1978 South Lebanon conflict, also known as the First Israeli invasion of Lebanon and codenamed Operation Litani by Israel, began when Israel invaded southern Lebanon up to the Litani River in March 1978. It was in response to the Coastal Road massacre near Tel Aviv by Palestinian militants based in Lebanon. The conflict resulted in the deaths of 1,100–2,000 Lebanese and Palestinians, 20 Israelis, and the internal displacement of 100,000 to 250,000 people in Lebanon. The Israel Defense Forces gained a military victory against the Palestine Liberation Organization (PLO) as the latter was forced to withdraw from southern Lebanon, preventing it from launching attacks on Israel from across its land border with Lebanon. In response to the outbreak of hostilities, the United Nations Security Council adopted Resolution 425 and Resolution 426 on 19 March 1978, which called on Israel to immediately withdraw its troops from Lebanon and established the United Nations Interim Force in Lebanon (UNIFIL).

Lebanon, officially the Republic of Lebanon, is a country in the Levant region of West Asia. Situated at the crossroads of the Mediterranean Basin and the Arabian Peninsula, it is bordered by Syria to the north and east, Israel to the south, and the Mediterranean Sea to the west; Cyprus lies a short distance from the coastline. Lebanon has a population of more than five million and an area of 10,452 square kilometres (4,036 sq mi). Beirut is the country's capital and largest city.