When the workers of all countries unite for the common cause of a creating a society where the capitalists and owners of the means of production do not control the lives and destinies of the 99% of human beings in the world, any such unity in Marxist thought is known as proletarian internationalism.
The goal of the struggle of the working masses including the peasants and landless serfs is primarily to defend themselves against the power and domination of the owners of means of production that they mostly use for augmenting their own wealth and upholding their privileges. The ideas about the unity of working classes to create a humane world has been the focus of theoretical and practical activities of generations of socialists since the founders of Scientific Socialism formulated their economic and political theories in the 19th century.
The first major step in creating a socialist society took place in Czarist Russia where the Bolsheviks under the leadership of Vladimir Lenin overthrew the old dynastic rule and introduced the Soviet system.
The success of the Bolshevik Revolution in 1917 was a catalyst for revolutionary activities of the working masses in many countries and also a clarion call to the colonized people to overthrow their colonial masters. As a result, anti-colonial struggles became a powerful force in many Afro-Asian countries. Many countries, big and small, succeeded in throwing off the yoke of European masters.
But in many instances the local ruling classes that emerged had their roots in privileged classes or groups. The struggle for political and economic exploitation became their sole interest. While such leaders plundered their own people and used the political system as a camouflage for furthering their interests, the plight of the poor people remained a non-issue for them. In any case, it is little consolation to the working class, poor or starving people that their “glorious” saviors and leaders have hundreds of millions of dollars stacked in secret banks accounts in Switzerland, France, Britain and America!
However, such exploitation and downright plunder is not incidental. It is endemic, and closely related to how the capitalist political and economic system works. As long as capitalism lives, such exploitation will have its sway. In the third world countries, the problem of institutionalized brainwashing coupled with the exploitation of religion and cheap deceptive slogans at the hands of the ruling elites will continue to play havoc with the people of many Afro-Asian countries.
No doubt, capitalism is wonderful for a few but a disaster for many. To address such issues, Karl Marx and Frederick Engels advocated socialist democracy and a socialist system in place of capitalism. To achieve that goal, political education of working class people is the first step and that education is part of the political activity that is expressed by the unity of the workers.