Part of the essense of Marxist theory and practice is the notion of Internationalism. I will attempt to present a brief and useful definition and explication of internationalism and ways of applying it.
The roots of internationalism are in French Revolutionary notions of human brotherhood or sisterhood and universal political rights. This bourgeois notion is given a revolutionary class character in the last sentence of the Manifesto of the Communist Party: "Proletarians of all countries, Unite!" Meaning that the working people involved in production all over the world have a common bond and interest in overthrowing the capitalist system and thier own national capitalists to create something like a world revolutionary state that would eventually wither away during a stateless mature communist era.
If one questiones wheather Marxists should want a world state, ask yourself about the alternative. Individual national states existing for the purpose of controlling the natural resources and labor within its borders? Of course not. Borders must be destroyed, the states that exist for the control of the workers by parasitic rulers (not just a polemic, they really exist at the expense of their hosts) must be smashed and replaced with democratic, popular, directly elected, immidiately revokable, provisional assemblies whose prime task is to break down the resistance of the propertied classes.
But what does this have to do with nationalism and internationalism? One reason why workers are not smashing the state apparatus is precisely the question of nationalism. The way toward revolution is precisely the question of internationalism. Just this evening a friend of mine remarked that the problem with Marxism is internationalism, that the workers are the most nationalistic people. Is this a problem with Marxism or a problem with the labor movement which has shown national chauvinist policies and often supports the anti-labor activities of its own imperialist government?
The proletariat's patriotism stems from their experience of loyalty to family and community. These concrete social relations are extended to encompass compassion for the whole nation. This is accomplished through learning patriotism from the family, schools, media, friends, work, in short most of society and its institutions reinforce, to varying degrees, patriotism to the nation. Thus, the source of national chauvinism, for the working class is rooted in their own sense of altruism and care for their family and community. The sources of internationalism, or the common ties of the world working class, spring from differnt sources. These must usually be either purposfully sought out or they must be arrived at through experience and struggle in the workplace or in other realms that bring humans together in nationally trancendent ways.
Patriotism for the ruling class, the bourgeoisie, stems from very differnt roots. Their patriotism stems from rational (value maximizing) self-interest. The logic is that the state exists and was constructed by and for the capitalists. It is in thier interest to support the mechanism of the state, foster its national institutions, traditions, and practices.This fostering and support contributes to the national feelings on the part of the workers. National feeling is further cultivated through state patronage of public goods and welfare projects meant to win the support of workers and the poor. National capitalists are in competition with other national capitalists for control of different markets, labor, resources, and power. The rulers do not die in wars but they are war's biggest planners and boosters. They must get the workers motivated to fight other workers in wars.
In an 1870 letter, reflecting on national division in Europe, Karl Marx wrote: “Every industrial and commercial center in England now possesses a working-class population divided into two hostile camps, English proletarians and Irish proletarians.” .” In the same paragraph Marx outlines the racial and national structures erected that divide the proletarians against themselves. English workers see the Irish as competitors that undercut them; they see themselves as part of the “ruling nation” and become allied with the bourgeoisie “…thus strengthening their dominion over himself. ( “Marx to Meyer and Vogt” in Letters to Americans, NewYork, 1953, p. 78).” Marx then extends his argument and compares this situation to the attitude of “poor whites” toward blacks in the postbellum American South.
Internationalism argues that workers of all countries are being exploited by capitalists, and should have no enmity between each other, only the common bonds of being human and being exploited. Thus, racial and national antagonisms only serve to deepen and secure the exploitation of workers. Those workers who receive preferential treatment should struggle against it and for the equal treatment of thier fellow workers in oppressed or disfavored national or racial categories. This logic also brings Marxists, especially after Lenin's interpretations, to struggle for national self-determination, for nations free from domination by other nations as part of the course for the goal of proletarian revolution. Of course all of these elements must be assesed by the facts on the ground, the true democratic desires of nations and peoples, through scientific enquiry, and not simple application of theory to the world, without analysis.
The task of Marxists is to represent an internationalist stance to the working class. To point out and to criticize the gross misdeeds of reformist left parties that believe that imperialist aggression carried out in the name of a humanitarian mission can be anything but a form of nationalism and the attempt to oppress another people. Under this logic Marxists can under no circumstances promote or defend wars undertaken by imperialist powers, such as the U.S., even in the name of humanitarianism. Behind the false assertions of human rights, lurks imperial aggression.
This is still a work in progress. Feel free to add input in the comments section.