There have been very dynamic changes in our ideas about human groupings coming out of the shakeups resulting from two world wars in the 20th century. Prior to that time, nations were formed roughly on the basis of similar needs, backgrounds and culture founded to a great degree on physical or geographical factors of proximity. As various units gained strength, there were attempts to extend these groupings through use of force, but for the most part, without a true psychological unity to hold these larger aggregates together, they tended to dissolve over time. However, within national boundaries there were still numerous different ethnic or language groups that never fully merged their identity despite geographic proximity. The concept of “self-determination” was put forward to represent the idea that disparate cultural or ethnic groups should be able to determine their own mode of governance. Of course, this concept was a threat to the status quo of existing States or Empires and was used primarily to garner support during the crisis of the war(s) rather than as a true expression of intention. Yet the idea has its own power in that it bases itself on true psychological unity, which is the touchstone of a viable, long-term stability in any human aggregate.
Sri Aurobindo notes: “It is true that nationhood still founds itself largely on the idea of race, but this is in the nature of a fiction. It covers the historical fact of a fusion of many races and attributes a natural motive to a historical and geographical association. Nationhood founds itself partly on this association, partly on others which accentuate it, common interests, community of language, community of culture, and all these in unison have evolved a psychological idea, a psychological unity, which finds expression in the idea of nationalism. But the nation idea and the State idea do not everywhere coincide, and in most cases the former has been overridden by the latter and always on the same physical and vital grounds — grounds of geographical, economic, political and military necessity or convenience. In the conflict between the two, force, as in all vital and physical struggle, must always be the final arbiter. But the new principle proposed, that of the right of every natural grouping which feels its own separateness to choose its own status and partnerships, makes a clean sweep of these vital and physical grounds and substitutes a purely psychological principle of free-will and free choice as against the claims of political and economic necessity. Or rather the vital and physical grounds of grouping are only to be held valid when they receive this psychological sanction and are to found themselves upon it.”
Sri Aurobindo, The Ideal of Human Unity, Part Two, Chapter 30, The Principle of Free Confederation, pp. 264-265