On 6 June 1982, Begin's government authorized the Israel Defense Forces invasion of Lebanon, in response to the attempted assassination of the Israeli ambassador to the United Kingdom, Shlomo Argov. The objective of Operation "Peace for Galilee" was to force the PLO out of rocket range of Israel's northern border. Begin was hoping for a short and limited Israeli involvement that would destroy the PLO's political and military infrastructure in southern Lebanon, effectively reshaping the balance of Lebanese power in favor of the Christian Militias who were allied with Israel. Nevertheless, fighting soon escalated into war with Palestinian and Lebanese militias, as well as the Syrian military, and the IDF progressed as far as Beirut, well beyond the 40 km limit initially authorized by the government. Israeli forces were successful in driving the PLO out of Lebanon and forcing its leadership to relocate to Tunisia, but the war ultimately failed to achieve its political goals of bringing security to Israel's northern border and creating stability in Lebanon. Begin referred to the invasion as an inevitable act of survival, often comparing Yasser Arafat to Hitler.