The major issue facing Qasim was that of Arab unity. The union of Egypt and Syria into the United Arab Republic (U.A.R.) early in 1958 had aroused immense enthusiasm in the Arab world. Despite strong Pan-Arab sentiment in Iraq, Qasim was determined to achieve internal stability before considering any kind of federation with the U.A.R. In turn the Egyptian president, Gamal Abdel Nasser, came to resent Qasim's rule and tried to bring about its downfall. 'Abd as-Salam 'Arif, a close supporter of Qasim but also an ardent Nasserist, toured Iraq, praising Nasser. In March 1959 Pan-Arab opponents of Qasim launched an open rebellion in Mosul. The bulk of the army remained loyal, and the uprising was crushed with little difficulty; Qasim removed some 200 army officers of whose loyalty he could not be certain. Among civilians he was forced to rely for support mostly upon communists, who were eager for a chance to strike at their right-wing opponents, the Pan-Arabs, and now pushed for a larger voice in the determination of government policy. Qasim resisted their demands, and several months later purged communist elements from the police and the army.