This relates to Jean Jacques Rousseau's emphasis on popular sovereignty ("general will"):

The government should be based on the collective will of the entire community
Nationhood and statehood are linked concepts
Nations want to maintain political independence; usually seen through the principle of national self-determination
The aim is to establish a nation-state (one nation within a single state)
The most desirable form of government is when a political organisation is founded on people who share a common identity
These people gain the right to self-government
Nationalism, therefore, acts to legitimise the authority of the governing body

Nationalism Core Values