The Arab National Movement was created to overthrow the Ottoman Empire and later to oppose the colonialist regimes which were imposed on the Middle East after World War I.
A separate Palestinian National Movement emerged when the League of Nations established a separate entity called "Palestine" as a British Mandate. It was opposed to Zionist infiltration and especially to the establishment of the State of Israel. Palestinians felt they were being punished for crimes committed against the Jews by the Europeans. Some also felt that Israel was aligned with the West against the East.
After the Nakba many Palestinians had hoped to become part of a Pan-Arab nation comprising Egypt and Syria. When this prospect vanished in the late 1950s Yasser Arafat and his associates launched the Palestian Liberation Movement (Fatah).
After the 1967 Six Days War this formed the basis of the Palestinian Liberation Organisation (PLO), which is now accepted as the mouthpiece of the Palestinian people.