Al-Asali spearheaded the Nasserist movement in Syria following the 1956 Suez Crisis, and Nasserist officials and army officers were promoted during his tenure. He was credited with convincing Quwatli, another pro-Nasser leader, to run for president again in 1955. Quwatli appointed al-Asali as his first prime minister after taking office. In January 1958 he appointed socialist leader Salah al-Din al-Bitar as foreign minister and tasked him with negotiating a full union between Egypt and Syria. President al-Quwatli and al-Asali travelled to Cairo to finalize the agreement and announced the United Arab Republic, under the leadership of Gamal Abd al-Nasser, on 1 February 1958. Al-Asali was appointed vice-president by Nasser the following day.