This thesis is a study on the use of military force in United States peacemaking in Lebanon between 1982 and 1984. It argues that the failure of the Reagan Administration to understand accurately the complex political landscape of the Lebanese Civil War resulted in the US and the Multinational Force in Beirut becoming intertwined in the broader Lebanese conflict. Because of this, President Ronald Reagan and Secretary of State George Shultz applied a policy focusing on military force with a vague peacekeeping vision which led to catastrophic US casualties. This thesis also argues that US policy in Lebanon was inaccurately designed because, from the outset, Washington did not see Lebanon as a key policy frontline. However, the Administration’...