Abstract: From its very inception, just before the First War, the doctrine of Arab nationalism was a doctrine of pan-Arabism. The doctrine, then as it took shape during these years, claimed that Arab, because they spoke Arabic, formed a distinct nation, which was entitled. As such to enjoy an autonomous political existence within the Ottoman Empire, or perhaps even to secede from it. The territory which the proponents of pan-Arabism then had in mind comprised the Arabian peninsula (considered by them to be the cradle of the Arab nation), Mesopotamia, and the Levant, i.e., the territories known as Syria, Lebanon and Palestine. Egypt was not part of the Arab world as they envisaged it. Since that time, the Arab world has been gotten its independence. The Arab Unity is still a very important and controversial subject. The Arab World (al-alam al-arabi), or still better, the Arab Fatherland (al-watan al-arabi), refers to that vast stretch of territory from the Atlantic Ocean to the Arab/Persian Gulf. It engulfed all the Arab countries. Arab unification movement has attempted, unsuccessfully, to achieve Arab unity. In this paper I intend to discuss why the Arab unification movement has not achieved this goal. The analysis deals with this paradox.