For example, in the early days of the Russian Revolution there was a very high standard of democracy which those fighting the revolution created.
In the early days soviet democracy prevailed, land and factories were turned over to peasant and worker soviets, the debt was canceled, the banks, trusts and cartels were nationalized... [it was] democratic to the core, in which the police and standing army were to be replaced by the armed people." (weissman) This was changed not by an internal failure, but because European and American forces both sent armies and provided military and monetary support to counterrevolutionaries within Russia.
The Civil War, brought on by the world bourgeoisie... [with] fourteen invading armies and the White 'contras' of the day... brought the end to soviet democracy.... [partly because] the advanced revolutionary workers had been killed in the Civil War; Bolshevism now governed a mass of war-weary, semiliterate peasants in a world in which the revolutionary advance had been halted."
As these paragraphs have discussed, the essence of socialism is in the solidarity of the working class and power to the working class. The working class cuts across all national borders, and is only strong when it is united. The Russian revolution became isolated and was eventually destroyed by Stalinism specifically because, many believe, it was not able to become international and the essence of socialism is international. "They adopted a state of siege stance." (Weissman)
If socialism is about the solidarity of the working class, nationalism is about the solidarity of the regionally or ethnically related group. Nationalism is, briefly, the idea that similarity of culture is the most essential and important social bond. Power, then, comes from being part of a wider group which has power. Nationalists generally do not promote any sort of economic class welfare, and chose to leave the economic class system intact, though they may attempt to assure that the lower classes are adequately supported to make the entire structure stronger. Power, in the nationalist position, is in the nation itself, in the state -- in fact, power is in being a uniform part of a cohesive whole which is strong enough to be dominant over some space. An argument offered by John Breuilly defines nationalism as follows, and the implications for power should be relatively obvious:
nationalist argument is a political doctrine built upon three basic assertions: a. There exists a nation with an explicit and peculiar character. b. The interests and values of this nation take priority over all other interests and values. c. The nation must be as independent as possible. This usually requires at least the attainment of political sovereignty." Power, then, is being funneled into the political sovereignty of the group, which is supposedly deserving of it because it's values take priority over all other values.
Historically, power in what would be considered "ideal" nationalist states tends to be more centralized than in similarly "ideal" socialist states, which is to say that nationalist theory is more accepting of authoritarian approaches to power, and has an instinct to suggest that the power and authority of the nation/state/group should over ride and make unimportant the minority. There are numerous examples of this tendency, many of which would tend to fall into the "fascist" category. (All fascism is nationalistic, but not all nationalism is fascism) as Mussolini once wrote, "The maxim that society exists only for the well-being and freedom of the individuals composing it does not seem to be in conformity with nature's plans.... If classical liberalism spells individualism,... Fascism spells government."
That said, though nationalism is perhaps best expressed through an authoritarian response that embodies, as it were, the collective national power into a collective national governing body, it is also possible for nationalism to be expressed through other forms of government. For example, even true democratic societies such as ancient Athens a have shown themselves capable of extreme nationalism and in those cases their democratic ideals even fed into the theory that their nations (or city-states, as the case might be) were better or more worthy than those around them. For example, America's republicanism (under the name "democracy") has often been held up by American nationalist as evidence that America is superior to every other nation because it is more free, more righteous, and more egalitarian than any other nation. One quote supporting --and typifying-- American nationalism says, "You belong to the greatest nation on the face of the earth. Yours is the only nation which has been victorious in war and never claimed any territory as a prize of conquest. Your people have given millions, even billions to the poor of the earth and never asked for anything in return." (Hinckley)
Of course, the precise truth of this statement is unimportant (America has actually claimed several territories in combat, including Puerto Rico and the Virgin and Samoa Islands, and frequently our international aid is bound up with military demands or vast national indebtedness) -- what is important is that it feels accurate to the people of America, and it accurately represent the image which the nation has of itself as a light on the hill, a beacon of democracy, and so forth. The importance of this example is that it shows that while nationalism may usually be associated with authoritarianism or fascism, it may alternately be a sign of more "advanced" nations whose civilization gives them such pride that they become nationalistic. A similar trend was, of course, seen in imperial Britain.
In conclusion, socialism and nationalism have one simple, basic difference from which all other differences arise -- this difference is entire in the world view. Socialists see the working class as the basis of all social functioning, and therefore believe in a wider political base (leading to democracies) and in addressing the world in social and economic terms. Nationalist see the ethnic or regional group as the basis of all social functioning, and therefore believe in consolidating that group as much as possible (leading to authoritarian governments or monolithic republics) while addressing the world in cultural and political terms.
Breuilly, John. Nationalism and the State. Chicago: University of Chicago Press, 1985. Archivedat: http://www.nationalismproject.org/what/breuilly.htm