It was Sykes-Picot that created this to begin with This was a construct by the British and French that ignored tribal and religious boundaries
Iraq first then Iran will devolve into regional mini states so will Syria over time
The Iraqi constitutional solution, which they missed, was to use the Swiss model of a confederation of cantons. The cantons have most of the power and authority and can be divided or merged as the people determine is necessary. That's the only way to keep a multi-cultural, multi-national state together, let the people live with others of their own group and run their own affairs.
They missed it. The politicians wanted more centralized power, so they have greater opportunities to screw their enemies and control sources of graft.