The Israeli invasions of Lebanon primarily refer to two major military operations: the first in 1978 and the second in 1982. The 1978 invasion aimed to create a buffer zone against attacks from the Palest Liberation Organization (PLO). This led to the establishment of a security zone in southern Lebanon. The 1982 invasion was more extensive, targeting the PLO and aiming to expel its forces from Lebanon. This operation resulted in the siege of Beirut and significant changes in the political landscape of Lebanon, including the rise of various militant groups and increased tensions in the region.