The civil war in Syria is emphasizing the increasingly fractured nature of "Arab" ethno-cultural identity -- and not just in the sense that it always had numerous sub-types like "Syrian Arab," "Egyptian Arab," "Iraqi Arab," etc. It is getting to the point where there is no coherent over-arching Arab identity to begin with, and where the distinctly non-Arab nation of Iran has greater influence in the region.
There is instead a growing cluster of identities around the two poles of barbarians (although they and their allies might use the term "noble savage") and civilization (whose enemies might label it urban degeneracy).
First, where did Arab identity come from? It served to group together the various peoples who were facing a common enemy who was unlike them, and who had been occupying their lands for centuries. No, that was not any European country, as Europe never colonized the Middle East and only oversaw their polities for a few decades after WWI.
It was the Ottoman Empire that had taken over much of the Middle East and North Africa (along with the Balkans). Ethnic identity is geographically rooted, and to the Arabs, the Ottomans might as well have come from outer space -- located well outside of the Fertile Crescent, in Anatolia and the circum-Aegean region, sealed off from the Middle East by large mountain ranges.
The most sustained opposition to Ottoman rule came from the tribes of the Arabian Desert that unified around the political clan of al-Saud and the religious clan of al-Wahhab, beginning in the second half of the 1700s and lasting until the Empire bit the dust after WWI, in which the Arabians played the leading role. The Arabians were never under direct occupation and rule, living in the desert that the Ottomans had no interest in.
And the geometry of their encounters with the Ottomans was more threatening than it was for other places in the Middle East -- the Empire began to surround them on all sides, running down the Red Sea coast to their west, the Persian Gulf coast to their east, and the Fertile Crescent to their north. Feeling like the walls are closing in all around you puts you in a more apocalyptic do-or-die mindset, rather than getting hit by an advancing wave from one direction only, where you feel like retreat is possible.*
After the Ottomans were driven out of the Middle East, the newly liberated groups all rejoiced as part of a single cultural group -- the Arabs, giving a nod to the leading role of the Arabian Desert tribes.
Their languages were re-interpreted to be mere dialects of the same language, Arabic -- again giving credit to the Desert tribes rather than the other regions. Thus, a person in Beirut spoke "the Levantine dialect of the Arabic language," rather than a person in Riyadh speaking "the Arabian dialect of the Levantine language" if the Levant had played the leading role in over-turning the Ottomans.
And the names of their new nations and political parties gave primacy to Arab rather than local identity -- e.g., the "Syrian Arab Republic," where the qualifier "Arab" lies closer to the head noun "Republic," while the qualifier "Syrian" lies farther away (it's the same in the original Arabic).
The Arab identity not only distinguished them from their former Ottoman rulers, but also from their Persian neighbors, who like the Anatolians are sealed off from the Arabian peninsula geographically -- and therefore ethnically -- by their own set of great mountains. Persia never fell to the Ottomans, so they could have led the charge against the Empire, but they did not, and so enjoyed no particular goodwill from the Semitic speakers who threw off the yoke themselves.
So far, so good in the post-Ottoman world -- Turks in Anatolia, Iranians in Persia, and Arabs in the Arabian peninsula and North Africa.
But with the waning of the original impetus behind Arab cohesion -- Ottoman expansion -- the various sub-types of the Arab identity felt less and less motivation to consider one another as working on the same big team toward a similar big goal.
Then, all it took was for one group within the Arab team to turn against the others, and the weakened cohesion would escalate to outright hostility -- not only in the material realm of armies and economies, but in the ethno-cultural realm as well. Suddenly, the offending group were not real Arabs, or were not acting like proper Arabs should -- or if they were, then the offended group no longer wanted to be part of the big Arab team, and would carve out their own identity distinct from being Arab.
It was the original expansionist group within the Arabs -- the Saudis, going since circa 1750 -- who continued to push to expand their influence throughout the Middle East, both materially and culturally. Their political leaders from the al-Saud clan are still aligned with the religious leaders from the al-Wahhab clan, and that means the spread of the fundamentalist strain of Sunni Islam (Wahhabism / Salafism), preferably at the barrel of a gun (jihadism), or if not, then through control over cultural institutions financed by oil wealth.
There is no longer a foreign empire for the Saudis to drive out -- Israel is mainly occupying Palestine, not the entire Middle East and North Africa like the Ottomans did, and the United States has never succeeded in militarily occupying and administering any part of the region, as much as they keep trying to.
That leaves Saudi expansion to target other members of the Arab world, especially if they are secular nationalist governments like Iraq and Syria, where the Saudis have sent jihadist militias to destabilize the societies. Still, expansionists seek to dominate even those neighbors who are similar, because just being similar doesn't make you the equal to the superior expansionist nation. The Saudis have been in a long bitter rivalry with Qatar, which most outsiders would lump in the same category of "backward Salafi monarchies from the Gulf" as Saudi Arabia itself. Yet in their drive to be #1, the Saudis have been zealous in trying to undercut #2 just to be sure.
Their larger preoccupation, though, is with Iran, whose sphere of influence has often included the eastern and northern parts of the Fertile Crescent, most recently during the 1700s. The United States has made that into reality once again by creating a power vacuum in Iraq after 30-odd years of weakening the secular regime there, allowing the long-time regional power of Iran to fill the void. An expansionist nation like Saudi Arabia does not want to see another nation expanding, which would set them on a collision course, so most of their concern is with containing Iranian influence.
As the targets of Saudi expansion all find themselves in the cross-hairs of the same group, it leads them to consider themselves as members of a single team, in strong opposition to the group that is targeting them. Materially, this means military alliances forming among Iraq, Syria, and Iran against the Saudis and their Gulf allies. Ethno-culturally, it leads people from the Fertile Crescent to increasingly shed their identity as "Arabs," as their main threat is the Arabians.
So far, those identities are local ones from before the Ottoman Empire, such as Lebanese, Phoenician, Canaanite, etc., for a person living in Beirut. Maybe Levantine or (Eastern) Mediterranean, if they're willing to join a regional identity -- but nothing that would encompass the Arabian Desert.
Right now, they have not joined a single big identity that opposes the expansionary forces of the Gulf jihadist nations. It is a seemingly very heterogeneous group -- the Shia of Iran, Iraq, Lebanon, and Syria; Christians anywhere; Alawites and Druze in the Levant; and urbanized Sunni, who are not the more easily radicalized rural Sunni.
In fact, it may be primarily a split between urbanized and rural groups -- religious minorities tend to cluster in urban areas, since greater population size allows for more specialization and diversity, whereas less populated rural areas do not and tend to have more homogeneous cultures.
In the Middle East, "rural" does not mean humble sedentary crop farmers, but proud nomadic livestock herders. The tension between settled peoples and nomadic peoples goes back to the origins of agriculture and pastoralism, with one side framing it as a struggle between civilization and barbarism, and the other side framing it as slavery vs. freedom.
So perhaps as time goes on, the no-longer-Arab targets of Saudi expansion will adopt a cultural identity that rises above their local identities -- the New Cradle of Civilization, to invert the pejorative connotation of the Saudi phrase "Shia Crescent". On the other side: desert barbarians.
Egyptians will probably go the way of the Turks and identify on a "local" level since they are a large region.
Interestingly, the Palestinians seem to be siding with the desert barbarian side of this re-alignment. Not only because that way of life is more a part of their history, lying so close to the desert and having a large Bedouin sub-population among them. But also because of their adoption of Muslim Brotherhood identity politics a la Qatar (Hamas, who replaced the secular nationalist PLO led by Arafat).
Palestinians are also more sympathetic, in general, to the jihadist side of the Syrian civil war just to their north. In the West, this has fractured the Palestinian solidarity movement -- it is no longer primarily about national liberation from a European colonial settler state (Israel), a transition that is expected to happen sooner or later. It is instead about the character that the post-Israel society will take -- one side wants it to be more like Lebanon or Syria, while the other side wants it to be more like Qatar or Saudi Arabia.
The barbarian-aligned faction of the pro-Palestine movement is larger and more influential, and has worked to marginalize the pro-Palestine faction that wants a secular nationalist government that would align with the civilized part of the Levant to their north.
It is not only Middle Easterners who find themselves caught in that tension, but also Westerners who don't have any stake in the matter. Those who consider Palestine part of the civilized Levant or Eastern Mediterranean want it to have a secular nationalist government, while those who view Palestinians as noble savages rebelling against a highly developed state like Israel, would rather let Hamas take over and form an alliance with Qatar.
On the ground, Palestine will likely end up as the western-most location of the desert barbarian identity, or at best a bridge region between civilization and barbarism.
That is why Westerners concerned with our foreign policy in the Middle East are already dividing their attention between focusing on Palestine or on Syria. They can already sense that in the short-to-medium term, those two will belong to different sides of a larger fault-line between modern and medieval. That intuition will be confirmed as the peoples of the region begin to discard Arab identity and take on the settled vs. nomadic identity.
* The last time the Arabian Desert tribes got totally surrounded by a foreign Empire was by the Sasanians from Persia -- and that led directly to the uniting of their tribes during the birth of Islam, and their explosion through the walls in all directions, leading to the Muslim conquests of the Middle East and beyond. This time has been no different qualitatively, although not so extensive quantitatively.
Lesson to folks in the region: do not surround the Arabian tribes on all sides ever again, or you'll provoke another apocalyptic Muslim army to fan out from the desert and wreak havoc on civilization.