Germany was (compared to Iraq) an ethnically and religiously homogeneous society with strong roots in Western rationalism.
Likely - as in Iraq today - we would have had a lot less success in places more similar to Iraq in this regard.
An example would be Yugoslavia, where totalitarian repression was required to tamp down these differences.
And where even 50 years later they boiled over - just as in Iraq as has soon as the lid was off - and it was impossible to hold the country together.
The Thirty Years' War began as a civil war and was fought between 1618 and 1648, principally on the territory of today's Germany.[snip]Wars of religion are often very bloody. Consider the The French Wars of Religion, (1562 to 1598)The major impact of the Thirty Years' War, which primarily used mercenary armies who had little concern for anyone's rights or property, was to lay waste to entire regions scavenged bare by the foraging armies, causing a much higher than normal death rate among the civilian population, as episodes of widespread famine and disease (a starving body has little resistance to illnesses) devastated the population of The Germanies and The Low Countries, while bankrupting many of the powers involved. [snip].
Germany's population was reduced by 30 % on average, in the territory of Brandenburg the losses had amounted to half, in some areas to a an estimated two thirds of the population. Germany’s male population was reduced by almost half.
were a series of conflicts fought between Catholics and Huguenots (Protestants) from the middle of the sixteenth century to the Edict of Nantes in 1598, including civil infighting as well as military operations. In addition to the religious elements, they involved a struggle for influence over the ruling of the country between the powerful House of Guise (Lorraine) and the Catholic League, on the one hand, and the House of Bourbon on the other hand. Hundreds of thousands of people were killed in these wars.Wikipedia has great lists of Civil Wars - past and present. They are not as uncommon as one might think at first.