Sassine was a signatory of the Taif Agreement that ended the Lebanese Civil War.[7] He was serving as Deputy Speaker of Parliament when Parliament signed the agreement on 22 October 1989 and ratified it on 4 November 1989. In the post-Taif period Sassine was appointed Vice-Prime Minister and Minister of Labor in both the 1990-1992 governments of Salim al-Hoss, and Omar Karami.[8]