Nobody can be a citizen of the world as he is the citizen of his country. Jaspers, in his Origin and Goal of History (1953), discusses extensively the implications of a world state and a world empire.
No matter what form a world government with centralized power over the whole globe might assume, the very notion of one sovereign force ruling the whole earth, holding the monopoly of all means of violence, unchecked and uncontrolled by other sovereign powers, is not only a forbidding nightmare of tyranny, it would be the end of all political life as we know it.
Political concepts are based on plurality, diversity, and mutual limitations. A citizen is by definition a citizen among citizens of a country among countries. His rights and duties must be defined and limited, not only by those of his fellow citizens, but also by the boundaries of a territory.
Philosophy may conceive of the earth as the homeland of mankind and of one unwritten law, eternal and valid for all Politics deals with men, nationals of many countries and heirs to many pasts; its laws are the positively established fences which hedge in, protect, and limit the space in which freedom is not a concept, but a living, political reality, Tile establishment of one sovereign world state, far from being the prerequisite for world citizenship, would be the end of all citizenship. It would not be the climax of world politics, but quite literally its end.
To say, however, diat a world state conceived in the image of sovereign nation states or of a world empire in the image of the Roman Empire is dangerous (and the dominion of the Roman Empire over the civilized and barbarian parts of the world was bearable only because it stood against the dark and frightening background of unknown parts of the earth) is no solution for our present political problem.
Mankind, which for all preceding generations was no more than a concept or an ideal, has become something of an urgent reality. Europe, as Kant foresaw, has prescribed its laws to all other continents; but the result, the emergence of mankind out of and side by side with the continued existence of many nations, has assumed an altogether different aspect from the one which Kant envisaged when he saw the unification of mankind “in a far-distant future.”
Mankind owes its existence not to the dreams of the humanists nor to the reasoning of the philosophers and not even, at least not primarily, to political events, but almost exclusively to the technical development of the Western world.
When Europe in all earnest began to prescribe its “laws” to all other continents, it so happened that she herself had already lost her belief in them.
No less manifest than the fact that technology united the world is the other fact that Europe exported to the four corners of the earth its processes of disintegration—which had started in the Western world with the decline of the traditionally accepted metaphysical and religious beliefs and had accompanied the grandiose development of the natural sciences and the victory of the nation state over all other forms of government.
Hie same forces which took centuries to undermine the ancient beliefs and political ways of life, and which have their place in the continuous development of the West alone, took only a few decades to break down, by working from without, beliefs and ways of life in all other parts of the world.
Excerpt From: Hannah Arendt. “Men in Dark Times.” iBooks.