At a press conference on Tuesday (full transcript), US Ambassador to Iraq, Zalmay Khalilzad, explained the provision:The Supreme Federal Court will be made up of a number of judges and experts in Sharia (Islamic Law) and law, whose number and manner of selection will be defined by a law that should be passed by two-thirds of the parliament members.
[T]here was a proposal to establish a constitutional court. There were concerns that the court might be a kind of religious court, checking whether the constitution is consistent with Shari'a, and that was eliminated. Instead the responsibility of the constitutionality of laws has been given to the Supreme Court, and there has been a discussion that since there are three standards that the constitution cannot violate, the laws cannot be against Islam, the laws cannot be against democracy, the laws cannot be against human rights. There need to be experts on those three things, added to the court. Since this will be a new responsibility for the court to have responsibility over the three sources: democracy, human rights, and Islam.
Now, in the balance of forces, given where things are, I think that that's not bad. These are decisions that I'm reporting, but these are the decisions that the Iraqis have made for themselves. We should also not forget our own country's history, that when we were debating the constitution, when we were ratifying the constitution in the United States some of our states had state religions. This country is in the process of being built on new principles, but these principles of course cannot be divorced from the history and traditions of Iraq. We do not want to impose a cookie-cutter approach that America is this kind of a Republic and you have to follow it precisely. No, that's not American foreign policy, that's not our style of dealing with other nations. We respect other peoples' traditions, but we also believe in universal values that are relevant for countries that want to succeed, that have demonstrated their relevance, to have. We have tried to encourage Iraqis to consider those, but of course this is their country and they have to make their own decisions ultimately.