We all have some idea of what a nationalist is: that's someone who hasn't done anything right since being born. But, what is nationalism, and where did it come from?
I agree with Eric Hobsbawm's distinction that nationalism is primarily a political program. ''It holds that groups defined as 'nations' have the right to, and therefore ought to, form territorial states of the kind that have become standard since the French Revolution.'' Various ideas of nationality existed before this time- Herder and Montesquieu were influential in terms of theory- but the political program of nationalism really emerges in the nineteenth century. It is a new way of putting forth collective claims, particularly the claim to statehood. It's worth noting that these claims were most successful in crumbling empires, such as the Habsburg and Ottoman.
There are actually two nationalist programs: the first is the claim that an ethnic group is distinct enough to require the formation of its own state; the second is that a particular 'nation-state' needs to somehow free itself of 'foreign influences'.
This gets to the problem with nationalism; while there are ethnicities in an anthropological sense, it does not follow that 'nations' even exist, and certainly not in the ways that they are often characterized by their members. And there are absolutely no states that are ethnically-pure in the modern world.
So, states that are defined by nationality eventually have to limit the political rights of minority ethnic groups: by legislating against those groups, killing them, making them part of the nation, moving them out, or suppressing them. In an evocative passage, Katherine Verdery writes: ''National symbolization includes... the process whereby groups within a society are rendered visible or invisible. For the project of nation-building, nonconforming elements must first be rendered visible, then assimilated or eliminated.''
Or, as Massimo d'Azeglio said after the unification of Italy, ''We have made Italy, now we have to make Italians.''