I believe your summary assumes too heavily that theology does not have any control, especially in modern republic and democratic governmental systems where voting is the norm. All Law big and small relies upon the good conscience of an individual to follow it. The American founding fathers understood this idea deeply, insisting that nothing matter how secure a secular government felt, ultimately it was being allowed to rule by the consent of the governed. Research into Nazi Germany and the Soviet Union will yield similar conclusions. These murderous states did not exist without a large amount of public support, in-fact, in the Soviet Union, 1 in 3 people would at one time or another report their friends and family to the communist authorities. Similarly too, there were plenty of instances of people willingly suffering in Gulags and dying in Concentration Camps due to the fervor of their zealot like support for these regimes.
Religion in its many myriad of forms and doctrines sits at one of the deepest foundational levels of human society. Acting as a belief system through which people interpret the world around them. No man secular or otherwise could have any freewill if he/she did not also have a belief system through which to filter stimulus and information. Foundational Belief is fundamental to decision making, and therefore, ruling over countries or not, Religion sits right at the beating heart of a government: it's people.
Of course it does. But organized religion exerting direct political power, through control of courts of judgment, control of family law, and the assertion of religious law (anti-blasphemy statutes, or mandatory church attendance, or church membership as a voting requirement, etc.) was the norm, and resulted in such a morally unsatisfying result that people harnessed government to systematically dismantle the enforcement authority of the church in their lives, to remove the hand of the priest and minister from the scepter of government and reduce them to the roles of counselors that one has the option of consulting. The payment of official churches through public taxes has also largely ended in the civilized world, forcing churches to actually appeal to people to voluntarily support them or wither up and die.
This development is the RESULT OF the abuse of people by organized religion, when it had power.
Of course, the fans of organized religion - the people who will actually DEFEND the likes of Calvin or Luther or Pope Leo and the murderous behavior of all of the official Christian Churches of the Reformation period - will decry the secularization of society by the demotion of religion to a private matter without public authority. The problem they have is history. The Church lost that power because it killed people.
Looking at society today, I would say that the secular state has become overmighty and over-intrusive. In America, the abusive nature of police power has gained attention - and resentment - as never before. Eastern Europeans in particular have already been through the worst of that, with the Soviet Union and the occupation of the Warsaw Pact countries. The result of the abuse of police power in the East has been that all of the formerly Catholic states of Eastern Europe, upon the departure of the troops of the USSR, substantially weakened the power of their governments and reduced the footprint of their police forces.
But those struggles within secularism - of how far people will tolerate secular government bullying them with thought police the way the Christian Church did centuries ago - is a page still being written.
If we may draw a lesson from history, it is that self-righteous prigs with power, be they Christian theologians or secular political philosophers, do not relinquish power without shedding rivers of blood, that they do so unrepentantly and believe themselves justified in doing so, and that in every generation there are always ill-formed, petty fanatics who will sign up with the Taliban, or the witch hunters, or the slave-hunter posses, or the segregationists, or the "error has no rights" crowd, or the fascists or the communist or "social warriors", and inflict great harm on some lives. In the process, they create religious and secular martyrs who ultimately inspire more people to shuck off the current Taliban.
People want some religion, some law and order, and they want to be left alone. Most people manage to balance the interests, and over time, the drift of societies of markedly different culture and religion is towards system where average people are not very much interfered with as they go about their lives. But the wannabee thought police, the Taliban, do gain control in places from time to time - Afghanistan, Riyadh, North Korea, Russia, Berlin, Salem, Geneva, the Vatican... - and when they do, they give humanity a foretaste of hell.
