Nations, States and Nation-States
Each person has a sense of attachment to a nation. Nationalism takes the shared sense of attachment to a particular nation and uses it to justify political action.
We frequently misuse the terms nation, state, and nation-state. States are defined by sovereignty over territory and a group of people. They are what we commonly call countries.  The United States, Great Britain, and Nigeria are all examples of states. Nations generate identity and loyalty. They are named groups who share common histories, myths, culture, economy, and rights. Ethnic groups also have a common ancestry and solidarity within the group, but they do not engage in the politics of nationalism. Americans are encouraged to sing the national anthem rather than the state anthem in order to become more integrated with the idea of a nation, even though it should be called the state anthem.
A nation-state would be a sovereign territory with one group of individuals who share a common history. Today, a true nation-state in the academic sense of the world does not exist. Nearly every state (country) in the world contains more than one national group.
Our definition of place included a form identity; how people view the place in which they live, or their sense of attachment to a larger place. National identity builds upon this definition and applies it to a specific nation. Namely, it is the idea that each person has a sense of attachment to a nation. In other words, they feel as though they belong to one nation more than any other. This attachment is formed by living in this nation and in doing everyday things that support the existence of this country — for example paying taxes, maintaining national armed forces, celebrating national holidays, and cheering on national teams in the Olympic Games or the World Cup. These types of actions create a sense of belonging, or identity, for a nation’s citizens. So, a person who has grown up in the United States attending fourth of July celebrations, cheering for the United States’ Olympic team, memorizing the national anthem, and paying taxes most likely has developed an American national identity.
It is important to recognize that each individual has a national identity, or an attachment to a particular nation. It is also important to note that when people do things in the name of their nation (such as singing a national anthem), they are really identifying with a state. This is why the misuse of the terms nation and state is such a powerful form of geopolitics: It generates a loyalty to the state through a national identity.
Nationalism takes the shared sense of attachment to a particular nation and uses it to justify political action. Nationalism is the belief that every nation has a right to control a piece of territory. Basically, if a group of people has a shared sense of nationalism, they form a “nation.” The idea of nationalism believes that once a group has defined itself as a nation they have a “natural right” to territory necessary to live in and govern in. In other words, nationalism is the belief that a nation should have its own state.
The ideology of nationalism claims that a nation is not complete without territory. It also says that the geopolitical situation is unjust, or unfair, if a nation does not have, or is not allowed to have, its own territory. Many people use nationalism to justify conflict, as each nation fights for its right to territory in which to live and govern.
The geopolitics of nationalism have resulted in millions of deaths as people fought to establish a state for their nation. For example, the United States of America was formed when a group of people had a shared sense of belonging (nationalism) that was separate from the government they lived under (the British crown). They fought, using their shared nationalism as the justification, to gain control of territory to call their own state, or country. Ultimately, they were able to gain their territory and form a state that reflected their sense of nationalism.
The United States continues to use nationalism as justification to protect the current territory it now holds. This pattern of people with a shared sense of nationalism fighting to gain control of territory is seen often throughout history and into contemporary times.|
 Colin Flint, Introduction to Geopolitics, 3rd edition, pp. 105-113