The nation state is a state that self-identifies as deriving its political legitimacy from serving as a sovereign entity for a nation as a sovereign territorial unit. The state is a political and geopolitical entity; the nation is a cultural and/or ethnic entity. The term "nation state" implies that the two geographically coincide. Nation state formation took place at different times in different parts of the earth but has become the dominant form of state organization.
The concept and actuality of the nation state can be compared and contrasted with that of the city state,   empire, confederation, and other state forms with which it may overlap. The key distinction from the other forms is the identification of a people with a polity.
See main article: Nationalism.
The origins and early history of nation states are disputed. A major theoretical issue is: "Which came first, the nation or the nation state?" For nationalists, the answer is that the nation existed first, nationalist movements arose to present its legitimate demand for sovereignty, and the nation state met that demand. Some "modernization theories" of nationalism see the national identity largely as a product of government policy to unify and modernize an already existing state. Most theories see the nation state as an 19th century European phenomenon, facilitated by developments such as mass literacy and the early mass media. However, historians also note the early emergence of a relatively unified state, and a sense of common identity, in Portugal and the Dutch Republic.
In France, Eric Hobsbawm argues the French state preceded the formation of the French people. Hobsbawm considers that the state made the French nation, not French nationalism, which emerged at the end of the 19th century, the time of the Dreyfus Affair. At the time of the 1789 French Revolution, only half of the French people spoke some French, and 12-13% spoke it "fairly", according to Hobsbawm.
During the Italian unification, the number of people speaking the Italian language was even lower. The French state promoted the unification of various dialects and languages into the French language. The introduction of conscription and the Third Republic's 1880s laws on public instruction, facilitated the creation of a national identity, under this theory.
The theorist Benedict Anderson argues that nations are "imagined communities" (the members cannot possibly know each other), and that the main causes of nationalism and the creation of an imagined community are the reduction of privileged access to particular script languages (such as Latin), the movement to abolish the ideas of divine rule and monarchy, as well as the emergence of the printing press under a system of capitalism (or, as Anderson calls it, print-capitalism). The "state-driven" theories of the origin of nation states tend to emphasize a few specific states, such as England and its rival France. These states expanded from core regions, and developed a national consciousness and sense of national identity ("Englishness" and "Frenchness").
Both assimilated peripheral nations (Wales, Cornubia, Brittany, Occitania); these areas experienced a revival of interest in the national culture in the 19th century, leading to the creation of autonomist movements in the 20th century.
Some nation states, such as Germany or Italy, came into existence at least partly as a result of political campaigns by nationalists, during the 19th century. In both cases, the territory was previously divided among other states, some of them very small. The sense of common identity was at first a cultural movement, such as in the Völkisch movement in German-speaking states, which rapidly acquired a political significance. In these cases, the nationalist sentiment and the nationalist movement clearly precede the unification of the German and Italian nation states.
Historians Hans Kohn, Liah Greenfeld, Philip White and others have classified nations such as Germany or Italy, where cultural unification preceded state unification, as ethnic nations or ethnic nationalities. Whereas 'state-driven' national unification's, such as in France, England or China, are more likely to flourish in multiethnic societies, producing a traditional national heritage of civic nations, or territory-based nationalities.  
The idea of a nation state is associated with the rise of the modern system of states, often called the "Westphalian system" in reference to the Treaty of Westphalia (1648). The balance of power, which characterizes that system, depends for its effectiveness upon clearly defined, centrally controlled, independent entities, whether empires or nation states, which recognize each others sovereignty and territory. The Westphalian system did not create the nation state, but the nation state meets the criteria for its component states (by assuming that there is no disputed territory).
The nation state received a philosophical underpinning in the era of Romanticism, at first as the 'natural' expression of the individual peoples (romantic nationalism: see Johann Gottlieb Fichte's conception of the Volk, which would be later opposed by Ernest Renan). The increasing emphasis during the 19th century on the ethnic and racial origins of the nation, led to a redefinition of the nation state in these terms. Racism, which in Boulainvilliers's theories was inherently antipatriotic and antinationalist, joined itself with colonialist imperialism and "continental imperialism", most notably in pan-Germanic and pan-Slavic movements.
The relation between racism and ethnic nationalism reached its height in the 20th century fascism and Nazism. The specific combination of 'nation' ('people') and 'state' expressed in such terms as the Völkische Staat and implemented in laws such as the 1935 Nuremberg laws made fascist states such as early Nazi Germany qualitatively different from non-fascist nation states. Obviously, minorities, who are not part of the Volk, have no authentic or legitimate role in such a state. In Germany, neither Jews nor the Roma were considered part of the Volk, and were specifically targeted for persecution. However German nationality law defined 'German' on the basis of German ancestry, excluding all non-Germans from the 'Volk'.
In recent years, the nation state's claim to absolute sovereignty within its borders has been much criticized. A global political system based on international agreements and supra-national blocs characterized the post-war era. Non-state actors, such as international corporations and non-governmental organizations, are widely seen as eroding the economic and political power of nation states, potentially leading to their eventual disappearance.
In Europe, in the 18th century, the classic non-national states were the multiethnic empires, (the Austro-Hungarian Empire, the Russian Empire, the Ottoman Empire, the British Empire) and smaller states at what would now be called sub-national level. The multi-ethnic empire was a monarchy ruled by a king, emperor or sultan. The population belonged to many ethnic groups, and they spoke many languages. The empire was dominated by one ethnic group, and their language was usually the language of public administration. The ruling dynasty was usually, but not always, from that group.
This type of state is not specifically European: such empires existed on all continents, excepting Australia and Antarctica. Some of the smaller European states were not so ethnically diverse, but were also dynastic states, ruled by a royal house. Their territory could expand by royal intermarriage or merge with another state when the dynasty merged. In some parts of Europe, notably Germany, very small territorial units existed. They were recognised by their neighbours as independent, and had their own government and laws. Some were ruled by princes or other hereditary rulers, some were governed by bishops or abbots. Because they were so small, however, they had no separate language or culture: the inhabitants shared the language of the surrounding region.
In some cases these states were simply overthrown by nationalist uprisings in the 19th century. Liberal ideas of free trade played a role in German unification, which was preceded by a customs union, the Zollverein. However, the Austro-Prussian War, and the German alliances in the Franco-Prussian War, were decisive in the unification. The Austro-Hungarian Empire and the Ottoman Empire broke up after the First World War and the Russian Empire became the Soviet Union, after the Russian Civil War.
A few of the smaller states survived: the independent principalities of Liechtenstein, Andorra, Monaco, and the republic of San Marino. (Vatican City is different. Although there was a larger Papal State, it was created in its present form by the 1929 Lateran treaties between Italy and the Roman Catholic Church.)
Nation states have their own characteristics, differing from those of the pre-national states. For a start, they have a different attitude to their territory, compared to the dynastic monarchies: it is semisacred, and nontransferable. No nation would swap territory with other states simply, for example, because the king's daughter got married. They have a different type of border, in principle defined only by the area of settlement of the national group, although many nation states also sought natural borders (rivers, mountain ranges).
The most noticeable characteristic is the degree to which nation states use the state as an instrument of national unity, in economic, social and cultural life.
The nation state promoted economic unity, by abolishing internal customs and tolls. In Germany, that process, the creation of the Zollverein, preceded formal national unity. Nation states typically have a policy to create and maintain a national transportation infrastructure, facilitating trade and travel. In 19th-century Europe, the expansion of the rail transport networks was at first largely a matter for private railway companies, but gradually came under control of the national governments. The French rail network, with its main lines radiating from Paris to all corners of France, is often seen as a reflection of the centralised French nation state, which directed its construction. Nation states continue to build, for instance, specifically national motorway networks. Specifically, transnational infrastructure programmes, such as the Trans-European Networks, are a recent innovation.
The nation states typically had a more centralised and uniform public administration than its imperial predecessors: they were smaller, and the population less diverse. (The internal diversity of the Ottoman Empire, for instance, was very great.) After the 19th-century triumph of the nation state in Europe, regional identity was subordinate to national identity, in regions such as Alsace-Lorraine, Catalonia, Brittany, Sicily, Sardinia and Corsica. In many cases, the regional administration was also subordinated to central (national) government. This process was partially reversed from the 1970s onward, with the introduction of various forms of regional autonomy, in formerly centralised states such as France.
The most obvious impact of the nation state, as compared to its non-national predecessors, is the creation of a uniform national culture, through state policy. The model of the nation state implies that its population constitutes a nation, united by a common descent, a common language and many forms of shared culture. When the implied unity was absent, the nation state often tried to create it. It promoted a uniform national language, through language policy. The creation of national systems of compulsory primary education and a relatively uniform curriculum in secondary schools, was the most effective instrument in the spread of the national languages. The schools also taught the national history, often in a propagandistic and mythologised version, and (especially during conflicts) some nation states still teach this kind of history.
Language and cultural policy was sometimes negative, aimed at the suppression of non-national elements. Language prohibitions were sometimes used to accelerate the adoption of national languages and the decline of minority languages (see Germanisation).
In some cases, these policies triggered bitter conflicts and further ethnic separatism. But where it worked, the cultural uniformity and homogeneity of the population increased. Conversely, the cultural divergence at the border became sharper: in theory, a uniform French identity extends from the Atlantic coast to the Rhine, and on the other bank of the Rhine, a uniform German identity begins. To enforce that model, both sides have divergent language policy and educational systems, although the linguistic boundary is in fact well inside France, and the Alsace region changed hands four times between 1870 and 1945.
Nigeria: 57 million people.
35 million Hausa and 22 million Ibo, who live in the same country.
In some cases, the geographic boundaries of an ethnic population and a political state largely coincide. In these cases, there is little immigration or emigration, few members of ethnic minorities, and few members of the "home" ethnicity living in other countries.
Clear examples of nation states (where ethnic groups make up more than 95% of the population are shown) include the following:(For further detail, please see the respective ethnic groups of the nation states mentioned as examples.)
The notion of a unifying "national identity" also extends to countries that host multiple ethnic or language groups, such as India and China. For example, Switzerland is constitutionally a confederation of cantons, and has four official languages, but it has also a 'Swiss' national identity, a national history and a classic national hero, Wilhelm Tell.
Innumerable conflicts have arisen where political boundaries did not correspond with ethnic or cultural boundaries. For one example, the Hatay Province was transferred to Turkey from Syria after the majority-Turkish population complained of mistreatment. The traditional homeland of the Kurdish people extends between northern Iraq, southeastern Turkey, and western Iran. Some of its inhabitants call for the creation of an independent Kurdistan, citing mistreatment by the Turkish and Iraqi governments. An armed conflict between the terrorist Kurdistan Workers Party and the Turkish government over this issue has been ongoing since 1984.
After WWII in the Tito era, nationalism was appealed to for uniting South Slav peoples. Later in the 20th century, after the break-up of the Soviet Union, leaders appealed to ancient ethnic feuds or tensions that ignited conflict between the Serbs, Croats and Slovenes, as well Bosnians, Montenegrins and Macedonians, eventually breaking up the long collaboration of peoples and ethnic cleansing was carried out in the Balkans, resulting in the destruction of the formerly communist republic and produced the civil wars in Bosnia and Herzegovina in 1992–95, resulted in mass population displacements and segregation that radically altered what was once a highly diverse and intermixed ethnic makeup of the region. These conflicts were largely about creating a new political framework of states, each of which would be ethnically and politically homogeneous. Serbians, Croatians and Bosnians insisted they were ethnically distinct although many communities had a long history of intermarriage. All could speak the common Serbo-Croatian Language. Presently Slovenia (89% Slovene), Croatia (88% Croat) and Serbia (83% Serb) could be classified as nation states per se, whereas Macedonia (66% Macedonian), Montenegro (42% Montenegrin) and Bosnia and Herzegovina (47% Bosniak) are multinational states.
Belgium is a classic example of an artificial state that is not a nation state. The state was formed by secession from the United Kingdom of the Netherlands in 1830, whose neutrality and integrity was protected by the Treaty of London 1839; thus it served as a buffer state between the European powers France, Prussia (After 1871 the German Empire), the United Kingdom and the Kingdom of the Netherlands until World War I. Belgium is divided between the Flemings in the north and the French-speaking or the German-speaking population in the south. The Flemish population in the north speaks Dutch, the Walloon population in the south speaks French and/or German. The Brussels population speaks French and/or Flemish.
The Flemish identity is also ethnic and cultural, and there is a strong separatist movement espoused by the political parties, Vlaams Belang and the Nieuw-Vlaamse Alliantie. The Francophone Walloon identity of Belgium is linguistically distinct and regionalist. There is also s unitary Belgian nationalism, several versions of a Greater Netherlands ideal, and a German-speaking community of Belgium annexed from Prussia in 1920, and re-annexed by Germany in 1940–1944. However these ideologies are all very marginal and politically insignificant during elections.
China covers a large geographic area and uses the concept of "Zhonghua minzu" or Chinese nationality, in the sense of ethnic groups, but it also officially recognizes the majority Han ethnic group which accounts for over 90% of the population, and no fewer than 55 ethnic national minorities.
The United Kingdom is a complex example of a nation state, due to its "countries within a country" status. The UK is a unitary state formed initially by the merger of two independent kingdoms, the Kingdom of England and the Kingdom of Scotland, but the Treaty of Union (1707) that set out the agreed terms has ensured the continuation of distinct features of each state, including separate legal systems and separate national churches.
In 2003, the British Government described the United Kingdom as "countries within a country". While the Office for National Statistics and others describe the United Kingdom as a "nation state", others, including a then Prime Minister, describe it as a "multinational state",  and the term Home Nations is used to describe the four national teams that represent the four nations of the United Kingdom (England, Northern Ireland, Scotland, Wales).
Israel's definition of a nation state differs from other countries as its concept of a nation state is based on the Ethnoreligious group (Judaism) rather than solely on ethnicity, while the ancient mother language of the Jews, Hebrew, was revived as a unifying bond between them as a national and official language.
Israel was founded as a Jewish state in 1948, and the country's Basic Laws describe it as both a Jewish and a democratic state. According to the Israel Central Bureau of Statistics, 75.7% of Israel's population is Jewish. Large numbers of Jews continue to emigrate to Israel. Arabs, who make up 20.4% of the population, are the largest ethnic minority in Israel. Israel also has very small communities of Armenians, Circassians, Assyrians, Samaritans, and persons of some Jewish heritage. There are also some non-Jewish spouses of Israeli Jews. However, these communities are very small, and usually number only in the hundreds or thousands.
Pakistan, even being an ethnically diverse country, is regarded as a nation state due to its ideology on basis of which it got independence from British India as a separate nation rather than as a unified India.   Pakistanis are strongly bonded by their Muslim identity, culture, heritage, a single national language (Urdu) and values in the subcontinent.
The most obvious deviation from the ideal of 'one nation, one state', is the presence of minorities, especially ethnic minorities, which are clearly not members of the majority nation. An ethnic nationalist definition of a nation is necessarily exclusive: ethnic nations typically do not have open membership. In most cases, there is a clear idea that surrounding nations are different, and that includes members of those nations who live on the 'wrong side' of the border. Historical examples of groups, who have been specifically singled out as outsiders, are the Roma and Jews in Europe.
Negative responses to minorities within the nation state have ranged from cultural assimilation enforced by the state, to expulsion, persecution, violence, and extermination. The assimilation policies are usually enforced by the state, but violence against minorities is not always state initiated: it can occur in the form of mob violence such as lynching or pogroms. Nation states are responsible for some of the worst historical examples of violence against minorities: minorities not considered part of the nation.
However, many nation states accept specific minorities as being part of the nation, and the term national minority is often used in this sense. The Sorbs in Germany are an example: for centuries they have lived in German-speaking states, surrounded by a much larger ethnic German population, and they have no other historical territory. They are now generally considered to be part of the German nation and are accepted as such by the Federal Republic of Germany, which constitutionally guarantees their cultural rights. Of the thousands of ethnic and cultural minorities in nation states across the world, only a few have this level of acceptance and protection.
Multiculturalism is an official policy in many states, establishing the ideal of peaceful existence among multiple ethnic, cultural, and linguistic groups. Many nations have laws protecting minority rights.
When national boundaries that do not match ethnic boundaries are drawn, such as in the Balkans and Central Asia, ethnic tension, massacres and even genocide, sometimes has occurred historically (see Bosnian genocide and 2010 South Kyrgyzstan riots).
See main article: Irredentism. Ideally, the border of a nation state extends far enough to include all the members of the nation, and all of the national homeland. Again, in practice some of them always live on the 'wrong side' of the border. Part of the national homeland may be there too, and it may be governed by the 'wrong' nation. The response to the non-inclusion of territory and population may take the form of irredentism: demands to annex unredeemed territory and incorporate it into the nation state.
Irredentist claims are usually based on the fact that an identifiable part of the national group lives across the border. However, they can include claims to territory where no members of that nation live at present, because they lived there in the past, the national language is spoken in that region, the national culture has influenced it, geographical unity with the existing territory, or a wide variety of other reasons. Past grievances are usually involved and can cause revanchism.
It is sometimes difficult to distinguish irredentism from pan-nationalism, since both claim that all members of an ethnic and cultural nation belong in one specific state. Pan-nationalism is less likely to specify the nation ethnically. For instance, variants of Pan-Germanism have different ideas about what constituted Greater Germany, including the confusing term Grossdeutschland, which, in fact, implied the inclusion of huge Slavic minorities from the Austro-Hungarian Empire.
Typically, irredentist demands are at first made by members of non-state nationalist movements. When they are adopted by a state, they typically result in tensions, and actual attempts at annexation are always considered a casus belli, a cause for war. In many cases, such claims result in long-term hostile relations between neighbouring states. Irredentist movements, typically circulate maps of the claimed national territory, the greater nation state. That territory, which is often much larger than the existing state, plays a central role in their propaganda.
Irredentism should not be confused with claims to overseas colonies, which are not generally considered part of the national homeland. Some French overseas colonies would be an exception: French rule in Algeria unsuccessfully treated the colony as a département of France.
It has been speculated by both proponents of globalization and various science fiction writers that the concept of a nation state may disappear with the ever-increasingly interconnected nature of the world. Such ideas are sometimes expressed around concepts of a world government. Another possibility is a societal collapse and move into communal anarchy or zero world government, in which nation states no longer exist and government is done on the local level based on a global ethic of human rights.
This falls into line with the concept of internationalism, which states that sovereignty is an outdated concept and a barrier to achieving peace and harmony in the world, thus also stating that nation states are also a similar outdated concept.
If the nation state begins to disappear, it may well be the direct or indirect result of globalization and internationalism. The two concepts state that sovereignty is an outdated concept and, as the concept and existence of a nation state depends on 'untouchable' sovereignty, it is therefore reasonable to assume that.
Globalization especially has helped to bring about the discussion about the disappearance of nation states, as global trade and the rise of the concepts of a 'global citizen' and a common identity have helped to reduce differences and 'distances' between individual nation states, especially with regards to the internet.
In direct contrast to cosmopolitan theories about an ever more connected world that no longer requires nation states, is the Clash of Civilizations theory. The proposal by political scientist Samuel P. Huntington is that people's cultural and religious identities will be the primary source of conflict in the post–Cold War world.
The theory was originally formulated in a 1992 lecture at the American Enterprise Institute, which was then developed in a 1993 Foreign Affairs article titled "The Clash of Civilizations?", in response to Francis Fukuyama's 1992 book, The End of History and the Last Man. Huntington later expanded his thesis in a 1996 book The Clash of Civilizations and the Remaking of World Order.
Huntington began his thinking by surveying the diverse theories about the nature of global politics in the post–Cold War period. Some theorists and writers argued that human rights, liberal democracy and capitalist free market economics had become the only remaining ideological alternative for nations in the post–Cold War world. Specifically, Francis Fukuyama argued that the world had reached the 'end of history' in a Hegelian sense.
Huntington believed that while the age of ideology had ended, the world had reverted only to a normal state of affairs characterized by cultural conflict. In his thesis, he argued that the primary axis of conflict in the future will be along cultural and religious lines.
As an extension, he posits that the concept of different civilizations, as the highest rank of cultural identity, will become increasingly useful in analyzing the potential for conflict.
In the 1993 Foreign Affairs article, Huntington writes:
It is my hypothesis that the fundamental source of conflict in this new world will not be primarily ideological or primarily economic. The great divisions among humankind and the dominating source of conflict will be cultural. Nation states will remain the most powerful actors in world affairs, but the principal conflicts of global politics will occur between nations and groups of different civilizations. The clash of civilizations will dominate global politics. The fault lines between civilizations will be the battle lines of the future.
Scholar Sandra Joireman suggests that Huntington may be characterised as a neo-primordialist since while he sees people as having strong ties to their ethnicity, he does not believe that these ties have always existed.