A lot can happen between now and the mid to late 21st century. It is of course fiction which often tries to explain itself more than the truth does.

But here we try to predict the near future to explain a fictional distant future which relies on its past future of our present. In the sense of it being a fictional story this is a sound foundation because we can't prove it either way since the near future which the distant future relies on is still unknown to us. So anything is possible.

My guess is by the time we get there, the chaos of the Middle East has transformed it in ways we couldn't anticipate from this point in time. It's not just the problems there, it's the problems with the way the world tries to deal with the problems there that make the possible futures of the Middle East so widely variable.

I think the writers knowing this chose it because it's the least defineable future from our present perspective. We'd have a much harder time imagining this to be feasible if it were in Europe or Canada where we (the western world) percieve a much greater economic and political stability to resist the development of a sovereign nation within it's boundaries. There is also a relation between the human fear of the Machines and much of what we don't understand about middle eastern culture. This region's ties to the origin of humanity have long been the catalist for conflict. So on the whole I'd say the location was chosen more for the feel of it than for an ultimate knowable logic about it.