On Oct. 1, the Israeli military launched its fourth invasion of Lebanon in 50 years.

Israel invaded the country for the first time in 1978 in response to a Palestinian Liberation Organization terrorist attack outside Tel Aviv, carried out by militants based in Lebanon. The war was followed up by a much larger invasion in 1982, an occupation of southern Lebanon until 2000, then another invasion in 2006. It was the last invasion that weighed heaviest on Israel during its current invasion of the country.