"The right of self-determination means that a nation may arrange its life in the way it wishes. It has the right to arrange its life on the basis of autonomy. It has the right to enter into federal relations with other nations. It has the right to complete secession. Nations are sovereign, and all nations have equal rights." Stalin, Marxism and the National Question
To speak or write about 'nations' doing this or that or having rights is a prime example of reification. Stalin was a revolutionary social democrat in 1913 when he wrote the above and like Stalin, most social democrats of the time thought similarly about the right of national self-determination. The ever growing move away from promoting class conscious praxis for the abolition of the wage system, toward what might be called 'progressive nationalism' on the eve of World War I, demonstrates how far the socialist workers' movement which Marx and Engels had been part of, had been coopted and folded into the dominant ideas of the capitalist epoch through reified thinking in general and political opportunism in particular.
As Marx critically observed about reification in The Holy Family Chapter VI
"Once man is recognised as the essence, the basis of all human activity and situations, only 'Criticism' can invent new categories and transform man himself into a category and into the principle of a whole series of categories, as it is doing now. It is true that in so doing it takes the only road to salvation that has remained for frightened and persecuted theological inhumanity. History does nothing, it “possesses no immense wealth”, it “wages no battles”. It is man, real, living man who does all that, who possesses and fights; “history” is not, as it were, a person apart, using man as a means to achieve its own aims; history is nothing but the activity of man pursuing his aims."
Nationalism is the political movement of the capitalist class (aka the bourgeoisie) to achieve domination of the producing classes through the establishment of its own political State. The conception of national sovereignty for the capitalist class develops within and emerges from the womb of feudalism, the system the bourgeoisie sublates via political revolution. Under feudalism, political power is held by the aristocratic class and sovereignty is in the hands of a monarch, aka the sovereign. Thus, the 'right of national self-determination' is the political program of those rulers in waiting who wish to impose the wage system on the majority, the working class.
Colonialism grew out of aristocratic class rule and the well learned historical examples for the projections of class power presented by the Romans, Greeks, Egyptians, Sumerian etc. slave owning classes. The primary difference between the ancient domination of slave producers within empires, from feudalistic empire building, was the ever growing wealth and consequent political power of the capitalist class, a class which began to seethe and chafe under aristocratic rule as its colonialist mercantilism expanded in historical tandem with the closing of the commons by aristocrats in search of private sources of wealth. Privatisation by by class ruled governments is hardly a new concept. Henry VII made vagabond (read 'unemployed) peasants criminals, having them hanged along the roadsides of his kingdom. However, the major political-economic consequence of the closing of the commons was the ever growing employment of displaced peasants as wage-labourers, the workers who created the product of their collective labour as commodities, owned by the employing class and made available in markets for sale with a view to profit. In the West, this roiling, ever wealth accumulating capitalist class began to show its political face in alliance with the landlord class in parliamentary institutions. In the ideological sphere the decline of feudalism was marked by the gradual decline of feudalist legitimising religions e.g. in Europe, the Catholic Church and with that decline, the rise of the Protestant movement with its work ethic and the ever dominating ideology, bourgeois individualism. "Dieu et mon droit" was dying.
Whether or not it is labeled 'progressive', nationalist ideology is based on the notion that the employers and the workers have class interests in common. But within the inherently exploitive wage-system, exploiters and producers have no class interests in common: Buyers do not have interests in common with sellers when they come to the marketplace for commodities. Anti-colonialist nationalism has been and is the struggle of nascent ruling classes to cement their sovereign rule over the producing classes of workers and peasants through the establishment of a political State. While the establishment of a capitalist political State may liberate the bourgeois from domination by monarchists or faraway colonial ruling classes, it does nothing, in terms of promoting the emancipation of the workers from wage-slavery.
"The emancipation of the working class must be the act of the workers themselves" This was the principle on which the First International was based. That principle is as true now as it was then. The wage-system existed then and it exists now, even within political States labeled, 'socialist'.
In order to emancipate themselves, the workers will have to abandon contemporary leftist mythologies concerning 'progressive nationalism', 'boring from within' the pro-capitalist trade unions and parties, as well as the absurdly conservative notion of, 'a fair day's wage for a fair day's work.' Until they do, they will continue to spend their lives, as they spend their money, as wage-slaves, all equal under the law, in their own identities, democratically voting for bourgeois to lead them in government, while competing with each other for approval-votes from employers--because, as bourgeois ideology goes, the only way one can be free is if, some other one is un-free. C'est la vie under the rule of Capital.