If you're a Western non-Muslim who points out that a government that does not have an established religion is incompatible with traditional Islamic teaching, establishment dhimmi pseudoscholar John Esposito will call you an "Islamophobe." If you're an internationally renowned Islamic teacher who says the same thing, John Esposito will call you a "reformist."
"Why is secularism incompatible with Islam?," by Yusuf Al-Qaradawi in the Saudi Gazette, June 11 (thanks to all who sent this in):
Secularism can never enjoy a general acceptance in an Islamic society. For Muslim societies, the acceptance of secularism means something totally different. As Islam is a comprehensive system of worship (Ibadah) and legislation (Shari'ah), the acceptance of secularism means abandonment of Shari'ah, a denial of the divine guidance and a rejection of Allah's injunctions. It is indeed a false claim that Shari'ah is not proper to the requirements of the present age. The acceptance of a legislation formulated by humans means a preference of the humans' limited knowledge and experiences to the divine guidance: "Say! Do you know better than Allah?" (Qur'an, 2:140)
For this reason, the call for secularism among Muslims is atheism and a rejection of Islam. Its acceptance as a basis for rule in place of Shari'ah is downright apostasy. The silence of the masses in the Muslim world about this deviation has been a major transgression and a clear-cut instance of disobedience which have produces a sense of guilt, remorse, and inward resentment, all of which have generated discontent, insecurity, and hatred among committed Muslims because such deviation lacks legality.
Secularism is (only) compatible with the Western concept of God which maintains that after God had created the world, He left it to look after itself. In this sense, God's relationship with the world is like that of a watchmaker with a watch: he makes it then leaves it to function without any need for him. This (baseless) concept is inherited from Greek philosophy, especially that of Aristotle who argued that God neither controls nor knows anything about this world.
This concept is totally different from that of Muslims. We Muslims believe that Allah is the sole Creator and Sustainer of the Worlds. One Who "...takes account of every single thing." (Qur'an, 72:28); that He is All-Powerful and All-Knowing; that His Mercy and Bounties encompass everyone and suffice for all. In that capacity, Allah revealed His divine guidance to humanity, made certain things permissible and others prohibited, commanded people observe His injunctions and to judge according to them. If they do not do so, then they commit Kufr, aggression, and transgression.