Guys, thanks for your comments, and apologies for the delay in responding!
1. I share your love for idle speculation. I’d say my fundamental difference with you lies elsewhere: you grew up/are very familiar with a country where federalism has worked pretty well (with notable exceptions, such as slavery and the Jim Crow laws), while I came from another where federal institutions are full of perverse incentives. So, whenever somebody proposes a federal arrangement, I immediately perceive the costs, while you’re more open to the potential benefits.
2. That said, I think an useful way for thinking about federal structures is to analyze the incentives faced by subnational governments. (a) Some subnational governments are accountable to domestic audiences, and thus they seek a federal structure where subnational governments retain considerable autonomy, including autonomy over taxation. This is the kind of federation that fosters tax competition and experimentation, with the US and the EU as good examples. (b) In other contexts, subnational governments are not fully accountable to domestic audiences (even with elections) and thus they devise federal institutions as mechanisms for extracting and distributing rents among themselves, and they use these rents to perpetuate themselves in power. Rather than keeping authority over taxation, they purposefully delegate their tax authority in the federal government to collect taxes for themselves. In other words, the federal government acts as a enforcer of a cartel: it establishes the same tax rate everywhere, collects the money, and distributes it between the states according to some highly politicized formula. This is the kind of federalism that predominates in Latin America: Argentina, Mexico, and to a lesser extent Brazil.
In sum, my point is that creating a federation among governments that are not responsive to voters will lead to the second type of federation. I don’t see the Middle East creating a fully functional federal system unless governments in the region become fully responsive to voters, which will require much more than competitive elections.
3. Michelangelo: I agree with 95% of what you say about Turkey and Israel, especially the EU part, and I obviously believe that it is a good thing these countries trade more and develop better relationship with each other. That said, the main reason why I don’t see these countries forming a federation is a more fundamental one: (a) that neither Turkish nor Israeli politicians have anything to win by creating a federal arrangement, and (b) given Turkey’s enormous size with respect to Israel, this problem is especially important from the Israeli point of view.