National as ideology is a normative idea; nations exist objectively and should have the right to self-determination.
Nationalism is both an idea of a history, a tradition, and one of obligation. (each individual not only belongs to a nations, but also owes the nation unquestioning obedience)
The modern idea of nationalism is a combination of
1. Enlightenment and liberal concept of self ruling community.
2. the French revolutionary idea of community of equal citizens.
3. German conceptions of a people formed by history, tradition, and culture.