Essentially, nationalism is the belief in a nation's right to self-determination. There are however many variants of nationalism, although the two more commonly known are civic nationalism and ethnic nationalism. The two are entirely different due to their unique definitions of a nation.
Civic nationalists are indiscriminate towards members of their nation with regard to their ethnicity, and thus prefer to define a nation more by its geographical borders and their struggle therefore is rather more focused on the preservation of culture
as opposed to race
. Under its not-so-charismatic leader, Nick Griffin, The British National Party is slowly shedding its ethnic nationalist past and becoming more a civic nationalist party, and some of its supporters and indeed some councillors are not Caucasian or British in origin.
Ethnic nationalists are often rather more authoritarian however and tend to define their identity not along cultural lines but along ethnic or racial lines. This therefore leads to their struggle being aimed more at the preservation of their ethnicity or race. A good example of an ethnic nationalist would be Hitler, though he is certainly an extreme form, and should not be seen to represent ethnic nationalists as an entity. It is a shame however that many ethnic nationalists are racist, which is often why nationalism is so wrongly synonymised with racism. The National Front is an ethnic nationalist party in the UK.
Contrary to popular belief, nationalism is most commonly a left-wing ideology. This is partly because many people wrongly associate authoritarian 'tough' stances with right-wing politics, when left and right on the spectrum is determined entirely by economic stance. Mainly however, nationalists tend to prefer a slightly socialistic economy as opposed to a capitalistic economy. They often oppose globalisation
in many forms, saying that the outsourcing of jobs to foreign lands increases unemployment in their homeland, which ultimately stifles the nation's ability to determine itself. It is no suprise then, that with that immigration and sometimes emigration is opposed.
Nationalists are not only concerned with the welfare of their own nations, although they do not wish to interfere at all in that of others, because they often believe that every nation has a right to self-determination. So when mass immigration occurs in their country, they are not only concerned that this might cause a dissolution of their culture/ethnicity and a strain on the national infrastructure (eg NHS, public transport etc), but also that it will certainly cause a dissolution of the migrant's homeland's culture/majority ethnicity and infrastructure due to the leakage of contributors to art, science and general employment (thus a general breakdown of that country's national self-determination).
Nationalists oppose wars fought for reasons that do not affect the national interest - the Iraq war was opposed by the entire nationalist community in the West. There is also often an environmentalist
wing to the nationalist's beliefs, particularly focusing on renewable energy and the maintainence of an independant energy supply.
Nationalism's birth was in England under the reign of King John.