The way forward towards human unity is not absolutely fixed. While the end result of unity may be inevitable, neither the form nor the process can be specified, as they depend on a lot of circumstantial factors, many of which are not yet even fully evident. Sri Aurobindo outlines the forms that appear to be most likely, and describes the process of development needed to get us there.
“There is likely to be either a centralised World-State or a looser world-union which may be either a close federation or a simple confederacy of the peoples for the common ends of mankind. The last form is the most desirable, because it gives sufficient scope for the principle of variation which is necessary for the free play of life and the healthy progress of the race.”
“The process by which the World-State may come starts with the creation of a central body which will at first have very limited functions, but, once created, must absorb by degrees all the different utilities of a centralised international control, as the State, first in the form of a monarchy and then of a parliament, has been absorbing by degrees the whole control of the life of the nation, so that we are now within measurable distance of a centralised socialistic State which will leave no part of the life of its individuals unregulated. A similar process in the World-State will end in the taking up and the regulation of the whole life of the peoples into its hands; it may even end by abolishing national individuality and turning the divisions that it has created into mere departmental groupings, provinces and districts of the one common State. Such an eventuality may seem now a fantastic dream or an unrealisable idea; but it is one which, under certain conditions that are by no means beyond the scope of ultimate possibility, may well become feasible and even, after a certain point is reached, inevitable. A federal system and still more a confederacy would mean, on the other hand, the preservation of the national basis and a greater or less freedom of national life, but the subordination of the separate national to the larger common interests and of full separate freedom to the greater international necessities.”
Sri Aurobindo, The Ideal of Human Unity, Part Two, Chapter 35, Summary and Conclusion, pp. 304-305