In 1983 the IDF withdrew southward and left the Chouf, and would remain only in the security zone until the year 2000. That led to the Mountain War between the Druze Progressive Socialist Party and the Maronite Lebanese Forces. The PSP won the decisive battle that occurred in the Chouf and Aley District and inflected heavy losses to the LF. The result was the expulsion of the Christians from the Southern Mount Lebanon.