Under Sharon, Israel continued to build upon the unprecedented coordination between the Israel Defense Forces and the South African Defence Force, with Israeli and South African generals giving each other unfettered access to each other's battlefields and military tactics, and Israel sharing with South Africa highly classified information about its missions, such as Operation Opera, which had previously only been reserved for the United States. In 1981, after visiting South African forces fighting in Namibia for 10 days, Sharon argued that South Africa needed more weapons to fight Soviet infiltration in the region. Sharon promised that the relationship between Israel and South Africa would continue to deepen as they work to "ensure the National Defense of both our countries". The collaboration in carrying out joint-nuclear tests, in planning counter-insurgency strategies in Namibia and in designing security fences helped to make Israel, South Africa's closest ally in this period. 1982 Lebanon War and Sabra and Shatila massacre As Defense Minister, Sharon launched an invasion of Lebanon called Operation Peace for Galilee, later known as the 1982 Lebanon War, following the shooting of Israel's ambassador in London, Shlomo Argov. Although this attempted assassination was in fact perpetrated by the Abu Nidal Organization, possibly with Syrian or Iraqi involvement, the Israeli government justified the invasion by citing 270 terrorist attacks by the Palestinian Liberation Organization (PLO) in Israel, the occupied territories, and the Jordanian and Lebanese border (in addition to 20 attacks on Israeli interests abroad). Sharon intended the operation to eradicate the PLO from its state within a state inside Lebanon, but the war is primarily remembered for the Sabra and Shatila massacre. In a three-day massacre between 16 and 18 September, between 460 and 3,500 civilians, mostly Palestinians and Lebanese Shiites, in the Sabra neighborhood and the adjacent Shatila refugee camp were killed by the Phalanges— Lebanese Maronite Christian militias. Shatila had previously been one of the PLO's three main training camps for foreign terrorists and the main training camp for European terrorists; the Israelis maintained that 2,000 to 3,000 terrorists remained in the camps, but were unwilling to risk the lives of more of their soldiers after the Lebanese army repeatedly refused to "clear them out." The killings followed years of sectarian civil war in Lebanon that left 95,000 dead. The Lebanese army's chief prosecutor investigated the killings and counted 460 dead, Israeli intelligence estimated 700–800 dead, and the Palestinian