FIRST there were five, then there were seven, now there are 20, although many believe that only two matter and some suspect that actually none do.
Welcome to the complicated world of the so-called "G" organisations, including the Group of 20 (G-20) currently holding its summit (today and tomorrow) in Russia's ancient capital of St Petersburg.
Do they matter? Yes, a great deal, although the snag is that all these organisations are subject to a relentless process of erosion and have to fight to remain relevant.
There is a good reason why such international groups, with their predictable "G" prefixes, keep on being created - because all the global challenges are interconnected, but global governance remains fragmented.
So, establishing an informal group with no charter, no headquarters and no permanent staff offers both immediacy and intimacy for politicians in need of quick solutions.
The prototype for all arrangements of this kind is the G-5, comprising the US, Britain, France, Germany and Japan, first convened by Mr George Shultz, the US Treasury Secretary under President Richard Nixon. Its origins were humble - to deal with the impact of high oil prices on the global economy.
The G-5 was expanded later to include Italy and Canada. After the end of the Cold War, Russia joined as well, in what was seen as a sign of goodwill. And then, after considerable delay, came the G-20 with its purpose of shepherding the world's economy through the massive financial crisis of 2008.
Instructively, all these G-efforts appear to be confined to global economic matters, largely because it is there that regulation structures need to adapt rapidly. But regardless of their history, all such organisations end up running into similar troubles.
They are instinctively seen as unrepresentative cabals, wishing to dictate to others. G-organisations try to shield themselves from such accusations by appearing inclusive. Issuing an invitation to the UN Secretary-General is a favourite trick, but so is the practice of inviting other heads of government for dinners and photo-opportunities.
Unsurprisingly, this never quite works, for those who are full members in a G-organisation still cannot hide their smugness, while those kept outside can't contain their resentment.
The pressure to increase membership is, thus, irresistible. Even the Bric grouping of Brazil, Russia, India and China - another G-outfit in anything but name - was compelled to expand by including South Africa.
But the need to retain relevance is never-ending, prompting such organisations to move beyond their initial purpose.
The G-8 suddenly started issuing statements against the "scourge of international terrorism" and even devoted an entire summit to "eradicating poverty in Africa", a debate which did not require any Africans to be present.
And as G-organisations get older, they get more bureaucratic. Countries hosting summits vie with one another in providing lavish hospitality.
The summit conclusions are written well in advance by so-called "sherpas"; by the time leaders arrive, they only need to sign on the dotted line and go home. The idea of an informal grouping discussing real issues is usually the first one to die when a G-organisation is successful.
Judged by such dispiriting standards, the G-20 did rather well. It has mobilised multilateral institutions to resolve fairly technical financial questions.
And it has been far better at outreach, not only encouraging small but high-income countries such as Singapore to bring their perspectives to the table, but also involving non-state actors such as business (B-20) and trade unions (L-20).
Still, the one unspoken but underlining challenge the G-20 has not succeeded in addressing is that which afflicted all other organisations - getting China to take an active role in not only attending, but in shaping activities.
The Chinese could have joined the G-8, but they deemed it was too rich, too white and too Western. China is in the G-20, but its participation is still formulaic - it knows what it does not want but it often keeps silent on what it wishes to see done.
That's why pundits are still inspired to invent "virtual" G-organisations which supposedly get around this dilemma.
The G-2, composed of just the US and China, is occasionally put forward as the true structure to rule the world. But there is also the G-0 concept invented by Mr Ian Bremmer, the boss of risk consultancy Eurasia Group, who claims that we live in a rudderless world and all G-organisations are hype.
But both arguments miss a point.
For a variety of practical reasons, China and the US cannot determine the world's governance alone, even if they wanted to; a variable geometry of institutions, some formal and some informal, remains essential to tackle global governance.
So, the current G-structure may not be neat or logical, yet it serves a function. And it keeps diplomats nimble.
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