In regard to the French Revolution ...
The end of the ancien regime, or the old order, moved the Revolution to a more radical phase for several reasons and in several ways:
The old order had been based on a social hierarchy of kings and nobles, along with ranking clergy, ruling over the majority population of the country. Once that social hierarchy was ended, there were questions of how fully equal all citizens should be under the Revolution's banner of "Liberty, Equality, Fraternity." The radical phase of the Revolution pushed for absolute equality of all citizens, which meant attacking also the wealthy bourgeois class of merchants and professionals. There were even some voices calling for what would essentially be a communist society. That was the message of François-Noël Babeuf (nicknamed "Gracchus" after the 2nd century Roman reformer). The change from a hierarchical society toward one in which there was more economic and political equality became gradually more radical.The old order was broken and didn't work well, but the new order established in the French Republic was not working well either. The economic problems of the nation persisted and were not easily solved. That led to more radical measures being imposed and implemented to try to balance the budget -- seizing lands that had been held by the church or the wealthy. The old order had demanded loyalty to an absolute monarchy. In ending that political model and creating a new republic based on the rights of individuals as citizens, the hope was that greater liberty and fraternity would exist in the nation. However, the new order found it necessary to enforce loyalty to the Republic and its ideas. That meant a more radical phase that demanded absolute loyalty to the new path of the nation. It got to the point that anyone who was suspected of disloyalty to the Republic was arrested and many were executed during what is called the "Reign of Terror." So the new order became as radically absolute in its loyalty demands as the old order had been in its traditional expectations.
