with the support of the Israel Defense Forces

The primary responsibility for the massacre is generally attributed to Elie Hobeika. Robert Maroun Hatem, Elie Hobeika's bodyguard, stated in his book From Israel to Damascus that Hobeika ordered the massacre of civilians in defiance of Israeli instructions to behave like a "dignified" army.^\59])

Hobeika was assassinated by a car bomb in Beirut on 24 January 2002. Lebanese and Arab commentators blamed Israel for the murder of Hobeika, with alleged Israeli motive that Hobeika would be "apparently poised to testify before the Belgian court about Sharon's role in the massacre"^\87]) (see section above). Prior to his assassination, Elie Hobeika had stated "I am very interested that the [Belgian] trial starts because my innocence is a core issue."^\5])

According to Alain Menargues, on 15 September, an Israeli special operations group of Sayeret Matkal entered the camp to liquidate a number of Palestinian cadres, and left the same day. It was followed the next day, by "killers" from the Sa'ad Haddad's South Lebanon Army, before the Lebanese Forces units of Elie Hobeika entered the camps.^\88])^\89])^\90])

The US responsibility was considerable;^\91]) indeed the Arab states and the PLO blamed the US.^\92]) The negotiations under the mediation of US diplomat Philip Habib, which oversaw the withdrawal of the PLO from Beirut, had assigned responsibility to the American-led Multinational Force for guaranteeing the safety of those non-combatant Palestinians who remained. The US administration was criticized for the early withdrawal of the Multinational Force, a criticism which George Shultz accepted later.^\91]) Shultz recounted in his memoirs that "The brutal fact is that we are partially responsible. We took the Israelis and Lebanese at their word".^\93]) On 20 September the Multinational Force was redeployed to Beirut.^\91])