Well, let's have a look at this description of yours, shall we?

As a movement, it presupposes the existence and tends to promote the interests of a particular nation, especially with the aim of gaining and maintaining its sovereignty (self-governance) over its perceived homeland to create a nation-state.

Oh yes... you are absolutely correct - I have no idea where I got the idea from that nationalization would be the most logical, direct and dependable method for a nationalist "to promote the interests of a particular nation" and "gaining and maintaining its sovereignty (self-governance) over its perceived homeland." There is no way state control over resources and industries could ever "promote the interests of a particular nation," could it?

Quick, somebody call Cuba - driving your citizens into abject poverty through privatized medical debt is how real nationalists do it.

that a nation is a natural and ideal basis for a polity, and that the nation is the only rightful source of political power. It further aims to build and maintain a single national identity, based on a combination of shared social characteristics such as culture, ethnicity, geographic location, language, politics (or the government), religion, traditions and belief in a shared singular history, and to promote national unity or solidarity.

This is not descriptive - it's just the pseudo-scientific gibberish used to justify nation sates which does absolutely no justifying whatsoever.

Naturally, what proposed benefit (if any) the existence of nation states offers to it's citizens doesn't form part of this description... which is telling.