On June 6, 1982, the Israeli Defence Forces entered Lebanon for what was billed as a relatively limited operation. In reality, the Lebanon War claimed many lives and undermined public trust in decision-makers. Through newly published archival documents, this book explores the events that led to the war and the actions of the people involved. With the help of documents published in this book for the first time, historian Yigal Kipnis lays out the circumstances of the war, the preparations and discussions leading up to and during it, Israel's convoluted moves against the administration in Washington and against the Lebanese Christians, and above all - the consistent coordination between Prime Minister Menachem Begin and Minister of Defense Ariel Sharon. The goals of the war were derived from Begin's worldview. Sharon worked to achieve these goals in the military field while Begin operated in the Israeli political field and diplomatically with the United States. To this end, he skillfully, cleverly, and decisively maneuvered between his principles and his obligations as a leader guiding a nation to war and to the political struggle for its justice. However, he was also subject to extreme emotional changes, as revealed by the detailed reports of his behavioral transformations by representatives of the US State Department. This book will be of interest to researchers of Middle Eastern political history, US-Israeli relations, and the Israeli-Palestinian conflict, as well as political science and political history.