Was Nationalism the Most Important Force of Change in Europe up to 1870?

Nationalism is the feeling of loyalty shared by a group of people united by race, language, and culture. It was born and spreading since 1789 during the French Revolution, and spread by the Napoleon army. To express their loyalty to their nation, people will attempt to fight for independence against foreign rule or unite themselves into one large nation-state. Nationalism therefore was both a uniting force and dividing force; uniting a number of small states into one large nation-state or splitting a large country into smaller ones. This feeling of nationalism therefore directed the people to make many territorial changes on the face of Europe.
First, we should look at changes made by nationalism to the Vienna settlement. Vienna settlement can be seen as a stage that attempts to stop changes from taking place in Europe: it aimed to "turn to clock back", restoring old order, and preserve a "status quo" to maintain balance of power and stability in return for peace. …