I don't really see the controversy, it's just a reframing of well-known issues about the conflict, using different terminology. For instance, there's obviously

I don't really see the controversy, it's just a reframing of well-known issues about the conflict, using different terminology. For instance, there's obviously an economic element to the conflict between the richer, more urban Shia Alawites who live principally in the Western part of Syria, and the poorer, more rural Sunni population. I have read that part of the destabilization is down to mass movements of the urban poor into the cities in the years running up to the conflict. And Saudi Arabia and other wealthy oil rich states clearly provide religious and armaments funding to support hardline interpretations of Islam, which means that the conflict between Shia and Sunni takes on a much more fundamentalist tone. That power arises from their wealth relative to other regions in the area. As I say, I don't think either of these things are particularly controversial. If we were talking about the rural poor moving into the cities in China, we wouldn't have a problem talking about it as an issue of income inequality. It seems quite obvious that this is a major issue in a lot of the developing world (where income inequality tends to be far higher than in the West, particularly in resource rich countries). I wouldn't say this has much relevance to policy in the developed world. It would be dubious if Piketty tried to use this to draw conclusions about the West, but I can't see he has done that.