Interesting article. I suspect that some of the analysis is slanted based on the intended audience. For example, the sentence

The tribes, meanwhile, are not sectarian but rather secular nationalists, concerned over all with their local power base and community. {emphasis added}
really appears, to me at least, to be aimed at an audience that has little or no understanding of what tribal identities and politics are all about. A sharp distinction between the "evil" sectarians and the "good" secular nationalists should play well with many Western audiences.

His point about integration, I don't think "re-integration" is the right word for this situation since that implies a previous integration, is well made as is his noting of the potential problems with the Sh'ia and Kurdish extant power blocks.