Decentralization of authority achieves the goals of peace, prosperity, and equality because it depends on trade. Two people that but for ideological or religious reasons would never have cause to interact are more than willing to ignore those differences and engage in the “just business” of trade. Once a trade relationship is established, a human relationship will soon follow. Trade humanizes the foreigner, stripping away their “other group” title leaving behind only the person. Trade then has the power to expand both our wealth in things and in each other.
The path to uniting humanity is more, not fewer, groups. We should be promoting the break up of states, not their mergers. If all countries could dispense with this Trumpian siege mentality that implies a country can’t be “great” unless it is also autarkic, the world could achieve the peaceful utopia that the one-world centralizers dream of. Spontaneous order works in Nature. We are a part of Nature. It will work for us as well if we can make the right choice to the only question that matters: shall our relationships be governed by force or choice?