The structures of all societies must be within certain boundaries dictated by the principle economic activity. If a social structure requires adjustment, the means of change is usually a crisis such as a war, a political revolution or even an economic catastrophe. The effect in each case is that when the society survives the crisis, it is then reformulated within the boundaries that are required by economic forces.
No great ideology actually mandates the necessary parameters for the correct political, social and economic structures for a society. The necessary parameters for successful working social structures are dependent upon a society's main economic activity and not upon high-minded political philosophies. Since political and economic systems are forms of control for societies, changes to these institutions are frequently tumultuous. If the social systems are not working, change must come; otherwise, the society will dissolve. The true reasons that changes occur are frequently masked, but deep analysis usually reveals that the actual causes are economic in nature.