In the Middle East yes.
It is not really true in the North Africa except for the Libya, which puts together two regions that never got along very well (and now again are split).
The Egypt of course is in its Nile valley a state and nation concept older than the europeans.
the three Maghrebine states, the Morocco, the Tunisia and the Algeria correspond mostly in their borders with the ancient polities and even the Ottoman period divisions.
Of course the cohesion in the North Africa is much greater, no accident in my opinion.
Yes this is true of the Syria.
Of course that does not make it true of the rest of the Arabic speaking region.
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No, this is a fallacious and grossly distorted timeline and understanding
(1) Nasser did not create the modern Egypt, Nasser made a coup d’etat over an already modern state apparatus,
(2) Nasser did not come to the Pan Arab idea until later in his consolidation of power, after the Nile valley projects he had did not work (and a primary focus on the Egypt)
(3) the renaming of the Egyptian state the United Arab Republic tin the short-lived Egypt-Syria union again was later that Nasser coming to power, and was not lasting.
You have a highly distorted timeline and understanding of the Egyptian example.
Overall the Egyptians came late to the idea of pan Arabism (a fact bemoaned by the ideologists like al Husri) and never really left their Egyptian first views.
Aside from the states directly bordering the Israel and the Palestine, which of course had… surprise a direct interest in the subject, I do not see any real creation of unities around the Israel. It does not stop wars between Arab states around the Yemen, around the Saharan borders, even occupations (Kuwait…).
Indeed it did not even lead the short-lived unity of the Egypt and the Syria as the United Arab Republic last, in the hottest and most real part of the idea of a pan Arab conflict with the Israel.
It is a mythology.
The same things were written about Dibble’s people and the African National Congress.
Drawing a deep conclusion about the Palestinians living under the pressure of the occupation in the West Bank does not tell me very much.