Good-looking, but not good. That proposal is basically a recipe for ethnic cleansing. The two obvious issues are Israel (I think I can guess what the plan is in that regard...) and the mountainous areas in north and north-east (inhabited by Turks and Kurds who will hate this plan with a passion). The Kurds can probably be coerced against their will, as OTL demonstrates, but annexing those Turkish areas means war... with a NATO member.
Reduce the plan to leave those areas out, and it just becomes a big North Arabian state, which would be more feasible. Still runs the risk of Sunni-Shi'a conflict, though-- but I suppose a secularist constitution with guaranteed rights for both groups (presumably based on "sovereignty of local communities") could probably keep that in check.
WARNING: Rambling ahead!
Or,
or we could have an anarchist society there in those borders. That way you solve all those sectarian problems although not instantly. From what I can tell, focusing on fostering a common working class culture is a pretty good way of dealing with sectarianism but you also need to deal with the physical boundaries between sects and people. In which case, going for a similar system to Switzerland in how ethnic groups and minorities are organized or copying
A Pattern Language's ideas on sub-culture boundaries is a good way to deal with this.
However, the Palestine-Israel conflict is going to need a somewhat different solution. An anarchist society would definitely take a "no state approach" to the Palestine-Israel conflict but, given that this anarchist movement, in order to be successful, would have to be Arab or at least native in some capacity I feel that this anarchist society would also be far more sympathetic to Palestine. This is going to be a tricky issue because I'm not entirely sure
how an anarchist society would deal with this problem and, for all intents and purposes, we want to avoid having a "Reconstruction" sort of travesty where all attempts at fostering peace are half-assed.
The best way, in my opinion, to deal with this problem without dislocating as little people as possible is:
1. To build new towns, cities, and homes for Palestinians. A cool way to do this is to have a sort of "World's Fair" for architects all around the world to show off new buildings and ideas for these Palestinian towns, cities, and homes (displaced or homeless Israelis would be included as well) and whether these plans come to fruition is based on what Palestinian communities or groups choose.
2. Give Palestinians the right to return.
3. Since Israel is a first world country and most first world countries have lots of unused buildings and housing that is vacant because their owners make more money off of them being empty rather than inhabited, all those buildings would probably be given to poor or homeless Israelis and Palestinians.
4. Organize the neighborhoods in a way where Israelis and Palestinians are separated but still mixed and integrated (this is what I was referencing with Switzerland and
A Pattern Language) so that, eventually they become mixed and tolerant of one another.
My goal, although very ambitious, is to make Palestinians and Israelis see each other as the same group 500 years into the future in the same way Arabs, despite their major differences, still have solidarity with one another.
For the Kurdish issue, it would be better to just let Rojava run itself. I would personally like it if Rojava or Democratic Confederalism extended into the entirety of Kurdistan as a whole. The way Iraqi Kurdistan is run is despotic and the rest of Kurdistan is under the oppression of Turkey and Iran. However, I would like for there to be a union between this Rojava Kurdistan and "Greater Syria" as well in a way similar to the EU. Open borders and economic activity as well as shared military commands.
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And, to go off-topic a bit, it kind of reminds me of the HRE for some reason. Idk why but the way it's borders are shaped and the diversity of the region itself. I would love if someone drew the internal divisions of this map in a manner similar to the HRE.
EDIT: Here's the stuff I was talking about:
Solving Ethnic Violence w/ Complex Systems
Sub-culture Boundaries from A Pattern Language
Mosiac of Sub-cultures