When we look at the units of societal organisation, we can see a difference between the nation state, which is the predominant form that maintains internal consistency today, and the multi-national empire, which exists, not because of internal consistency necessarily, but because of the use of some form of external force or power to hold disparate national units together in a larger unity. The national unit tends to maintain a cultural homogeneity within its borders, and is, for the most part, held together by common language, culture, religion or economic and political systems within its borders. The result is that imperial units tend to be less stable and are subject to dissolution when the central force holding them together weakens enough to allow the nation units contained within to spin off.
This is an issue that impacts the development of larger formations as it is the core of agreement within the nation state that makes it a much more stable form than the empire.
Sri Aurobindo, writing in the period between 1914 and 1920, commented on this issue: “At the present stage of human progress the nation is the living collective unit of humanity. Empires exist, but they are as yet only political and not real units; they haev no life from within and owe their continuance to a force imposed on their constituent elements or else to a political convenience felt or acquiesced in by the constituents and favoured by the world outside.”
When the British Empire eventually dissolved, it morphed into the British Commonwealth of Nations, a looser confederacy based on the independent nation states developing certain cooperative, primarily economic, relations among and between each other. The key concept emphasized by Sri Aurobindo is the internal unity of the people and culture which binds them together into a stronger unit than a purely external political, economic or mechanical form of unification. The political unit is clearly a less favored form for developing true human unity than the development of a real sense of oneness, based on the spiritual development of humanity, among all beings regardless of culture, race, language, religion or other secondary characteristics.
Sri Aurobindo, The Ideal of Human Unity, Part I, Chapter 5, Nation and Empire: Real and Political Unities, pp. 34-35