In the spring of 1958, barely a month after forming a union with Syria, Egyptian President Gamal Abdel Nasser established a new union between the United Arab Republic and Yemen. As a gesture of goodwill and solidarity with the UAR, the Ba'ath Party was allowed to establish a branch in San'a. Both Egypt and Syria supported the republican forces in Yemen, and thereby encouraged Sallal's regime to take a similar regional stance regarding the occupation of Palestine. Sallal's visit to Damascus in early summer of 1963 was widely publicized in the Arab press as a sign of unity and a revival of all progressive, anti-imperialist forces. In 1964 Yemen joined twelve Arab states at a summit in Cairo, whose purpose was to plan reprisals against Israel for its diversion of the Jordan River. During the civil war between Royalists and Republicans in Yemen, Egypt supported the Republicans while Israel, Iran and Saudi Arabia supported the Royalists with war material and training.