I think a limited exchange is the better way, given that in the Middle East they also went nuclear. If only a few cities are hit, there's chance that the consequences stay local, and the rest of the World may just brush it off with nary a thought. So, Teheran is gone, won't be missed. The capital of Jordan's been nuked, what was it called again? A full blown scenario on the other hand, may have dire consequences in terms of fallout (I mean the actual fallout, not the game) even if no major power are involved.
About the Middle East, there are two massive wars that erupt on the region before the present-day of the story, for the first war, I had in mind that only Iran, Saudi Arabia, and Israel were hit, I do not know if other countries were hit by Iranian nukes as well, but because this scenario is an Israeli & Sunni alliance vs. Shia conflict, they could have, however, Iran's priority was to first and foremost destroy Israel and Saudi Arabia, not other "minor" countries.
Following the first conflict, Iran and Saudi Arabia were partitioned into various separate states think of the Morgenthau Plan for the Middle East in Sorairo's The Footprint of Mussolini on steroids, a good portion of these statelets are artificial states who were created just for the sake of it to show that a new era for the Middle East had begun, they have no way to properly function on their own and would eventually return to being part of their previous state after this second devastating Middle Eastern war, in the first conflict, Israel was the only one that was more or less "unaffected".
I am thinking of showing this thread how the Middle East looks like after both conflicts, but I am apprehensive to do so because it would reveal way too many aspects of my book.
Political and economic repercussions may be more tricky, but also more interesting. Major exchange, you basically have Fallout (the game) but a limited, local scenario begs a few questions. Have the oil fields been hit? Does it even matter, if the rest of the world's going green anyway?
The oil fields have indeed been hit, in an old map the nuclear-affected areas reflect the real-life locations of oil fields, but the world is using other alternative fuels as well.
Has Jerusalem been hit, or is the land around Mecca irradiated, making the city unreachable? How did the religious people reacted all over the world?
In the first conflict Jerusalem was not hit, but later in the second conflict I am thinking that it was indeed hit, I am currently not sure if Mecca was/will be hit, but as of now I had in mind that no, both Mecca and Medina are safe (unless if Iran was insane enough to nuke the holiest site in their religion), both of them were in fact been turned into Vatican-esque city-states opened to Muslims of all denominations, however, I am thinking that eventually they would be re-absorbed into the Hejaz state that surrounds them, but I really like this Mecca Vatican idea, I wanted to keep it but I am not sure if they would be feasible.
How did the religious people reacted all over the world?
I would like to say but the main point of my story is the religious point of view of such conflicts and geopolitical situation, so I prefer to be silent on this for now.
Is the International Community sending help to the affected areas and/or are people trying to escape their countries in ruins, thus causing an unprecedented refugee crisis?
A mixture of both.
About the map itself, there's nothing much I can say. For all I know, India is a polluted, overcrowded, ethnically tense mess even without a nuclear war, and without a central government keeping it all together, these problems are going to explode tenfold, doing potentially more damage than the bombs themselves.
So, balkanize India and Pakistan as much as you can, in the most violent way that you can.
This is pretty much what I am doing, but I am using pretty cliche provincial borders for them (Kashmir, Punjab, Sindh, Northeast India, Tamil Nadu but colored as independent)
If the world stay focused on the Middle East, India may even be second tier and become another forgotten tragedy like the many wars in Africa. Even on purpose: with the World in shock after what's happened, and too busy trying to deal with tons of refugees in the Mediterranean, and a level of street violence in India that makes Warhammer 40k look like cupcakes, people may find themselves unable to cope and prefer to ignore it. Even if some ONG or the Red Cross do intervene, they'd just give up after a while, overwhelmed by the hopelessness of the situation. It sounds a bit extreme, but you could even color the whole of the Indian Subcontinent (what's left of it anyway) as Terra Nullis.
I am not even sure if I will keep this green/black effect of the fallout in my maps, The Footprint of Mussolini also has nuclear proliferation in the Middle East, but all of their maps only shows the new borders of the countries hit by nukes, not the no-mans-lands, by the time that I am writing this, at least for now I have removed this green area thing.
Either way, thank you for your critique, it really, really helps me getting more organized, I do not post in map threads nor ask for opinions and advice, but I am needing these a lot right now.