Setanta,
The idea of earthly authority as an extension of heavenly authority is not at all knew. In ancient Mesopotamia kings were also the highest priests and the state was viewed as the domain of the God. Expansion of the state was viewed as an expansion of the power of its god. The laws of the state were identified as the will of the god.
Revealed law is such as was given to Moses and Mohammed. It is argued by some that this is the whole law and the law by which Islamic States should be governed. An Islamic State is one which closely adheres to that view. The Saud Kingdom is an example.
I was not taking a position. I suggested a possibility that establishment of Islamic States may be a necessary pre-condition for the evolution of secular governments which muslims will accept. I think you will agree that many muslim secular governments are under pressure from those who aspire to Islamic govrernment. There are many examples, Pakistan, Egypt, Iraq and Algeria are some. I believe that the reformers will prevail and States such as Iran will be common. As in Iran the nature of government will change. I hope for an eventual separation of religion and state that is generated by the wishes of the people. In the meantime I think we must adjust our thinking and learn to treat with Islamic States.
I take onboard your references to Turkey and will consider. My first thought is that Saddamism was a perverse variation of Kemalism. I also wonder how history would have judged Kemal had he not become Atatürk.
There is an article discussing revealed law at the link below.
http://www.sunnah.org/tasawwuf/shariah_tariqah.htm
I apologise for my poor writing skills and hope the above is more easily deciphered.