I highly recommend the haunting animated film Waltz with Bashir by Ari Folman. It's the story of an Israeli veteran of the Israel-Lebanon war of 1982 and his coming to terms with that war and massacre at the Sabra and Shatila refugee camps.

Israel invaded Lebanon and installed their ally Bashir Gemayel, senior commander of the "Phalangists" Christian militia. As the movie's website notes

Gemayel was considered extraordinarily charismatic, a fashionable young man, handsome and infinitely admired by all Christian militia soldiers and their families. He was especially esteemed by the Israeli leadership. Gemayel’s appointment as President of Lebanon was designed to ensure relative quiet on the tense border between the two countries.

While giving a speech at the Phalangist headquarters in East Beirut, Bashir Gemayel was killed by a massive explosive charge. To this day it is unknown who was responsible for the murder, but the assumption is that the assassination was orchestrated by Syrian or Palestinian factions or that they collaborated thereon.
That afternoon, Israeli troops penetrated a region in West Beirut that was mostly populated in those days by Palestinian refugees, and they surrounded the Sabra and Shatila refugee camps. Towards evening, large Phalangist forces made their way to the area, driven by a profound sense of revenge after the killing of their revered leader. At nightfall, Phalangist forces entered the Sabra and Shatila refugee camps aided by the IDF’s illumination rounds. The declared objective of the Christian forces was to purge the camps of Palestinian combat fighters. However, there were virtually no Palestinian combat fighters left in the refugee camps since they had been evacuated on ships to Tunisia two weeks earlier. For two whole days the sound of gunfire and battles could be heard from the camps but it was only on the third day, September 16th, when panic-stricken women swarmed the Israeli troops outside the camps, that the picture became clear: For three days the Christian forces massacred all refugee camp occupants. Men, women, the elderly and children, were all killed with horrific cruelty. To this day the exact number of victims is unknown but they are estimated at 3000.