The golden years of the British Commonwealth were the thirty years between 1926 and 1956. The Balfour Declaration of 1926 signified the beginning of the successful transmutation from Empire to Commonwealth with this sublime statement:
The Committee are of the opinion that nothing would be gained by attempting to lay down a Constitution for the British Empire, [which in the case of the self-governing components] are autonomous Communities...equal in status, in no way subordinate one to another in any aspect of their domestic or external affairs, though united by a common allegiance to the Crown and freely associated as members of the British Commonwealth of Nations...
Every self-governing member...is now the master of its destiny. In fact, if not always in form, it is subject to no complusion whatever. But no account, however accurate, of the negative relations in which Great Britain and the Dominions stand to each other can do more than express a portion of the truth. The British Empire is not founded on negations. It depends essentially, if not formally, on positive ideals. Free institutions are its life-blood. Free cooperation is its instrument. Peace, security and progress are among its objects.Alas, the free and equal partnership that took shape over this thirty year period, which held so much promise, and superceded what Disraeli called the "the Empire of England" and Seeley called "Greater Britain", quickly fell apart after the Suez Crisis, when the separate realms diverged politically, economically and culturally, even though they had so much in common.
And this is precisely why so many in Britain are having a difficult time stomaching the EU, which stands for very different values and is heading in a fundamentally different direction. As Peter Hitchens asks Prime Minister Cameron:
Hasn’t he noticed how the EU works? Its sclerosis is not the result of a failure of will. It is the consequence of it being the thing that it is, centralised, governed by dogma, lacking... a ‘demos’ or people to whom its councils are responsible, hugely too big to be controllable, and so too distant from oversight of any kind, inevitably corrupt and wasteful. It is, like so many stupid, doomed human institutions, yet another attempt to build the Tower of Babel, though on this occasion they didn’t even have a common language when they started.If the European project was about creating a European Commonwealth of Nations, instead of a centralising; federating; bureaucratic; elitist one, then that would be dandy. But at root the EU is a supranational effort designed to transcend and ultimately override the nation-state. It's essentially a vanity project motivated by superpower envy so its elites can imagine standing tall with the USA and China. Is this what the world needs? Is this what Europe wants?
The Commonwealth has a different vision for the world (it doesn't really have a vision, so this will be putting words in the mouth of its members), and I can't put this better than the author of "Who Killed the British Empire":
The fact that [the Commonwealth] demands no exclusive loyalty, that it seeks to establish no political orthodoxy, that it encourages it members to join in other associations of peoples, is an advantage, for today the world needs not rigid, all-inclusive international organizations, but a multiplicity of contacts, of circles of association to dissolve its antagonisms on many levels.
If the nation-state is in terminal decline (there is some truth in this, but is largely an overblown hypothesis) because of globalization and technology, then what the world needs is not bigger states and bigger governments, but a stronger network of cooperation, association and civil society which is the friend of freedom everywhere. That is why the Commonwealth will rise again.