A quite extraordinary insight into how high-stakes global politics were played in Copenhagen has emerged from an off-the-record briefing given to American reporters as they flew back to Washington from the climate change conference.
The briefing was given by a senior Obama administration official on board the Presidential aircraft after several hours of sometimes farcical, 11th-hour negotiations between the US and China, the world's two biggest emitters of greenhouses gases.
Here's the picture that emerges from an account of the briefing that I've seen. (Needless to say, I was not on board Air Force One myself.)
By early Friday evening, the last day of the conference, President Obama had decided he needed another one-on-one meeting with the Chinese premier Wen Jiabao. They'd already had a private meeting earlier in the day, but at follow-up sessions, the Chinese had sent only relatively junior officials.
Obama also wanted to set up meetings with Prime Minister Manmohan Singh of India, President Luiz Inacio Lula da Silva of Brazil, and Jacob Zuma of South Africa. But for some reason, his schedulers had great difficulty in nailing down times for these encounters.
So when Barack Obama arrived for his 7pm appointment with Wen Jiabao, imagine his consternation to discover the Chinese premier already locked in discussions with - wait for it - Messrs Singh, Lula and Zuma.
If the US president didn't exactly gatecrash the meeting, he certainly invited himself in. And that was when the Copenhagen Accord finally took shape, endorsed by the US, China, Brazil, India and South Africa.
It may well be that when the history of the 21st century comes to be written, that will be seen as the moment when the new world order was born.
What strikes you about those five countries? Try comparing them with the five permanent members of the UN Security Council, the traditional Big Powers: where's the UK? Or France? Or Russia?
This, I think, may turn out to mark the dawning of the new geo-political reality. (I do not, of course, expect the Brits, the French or the Russians to agree.) After all, India and Brazil, like China, are rapidly emerging economic super-powers; and South Africa is the undisputed economic power-house of Africa.
China, as a power only beginning now to understand how these global games are played, has identified them as the nations it needs to do business with.
The British energy secretary seems to see things much the same way in an article in today's Guardian: "The old order of developed versus developing has been replaced by more interesting alliances."
So was China to blame, as US and EU officials are claiming, for the weak final text of the Copenhagen Accord?
Certainly, it seems China was not prepared to agree to a defined greenhouse gas emissions target being specified in the text. (The EU was pressing for a global emissions reduction target of 50 per cent of 1990 levels by 2050; and an 80 per cent target for industrialised nations.)
In China's eyes, that would almost certanly have meant signing up to far deeper emissions cuts than it's prepared to countenance - remember, it may now be the world's biggest emitter of greenhouse gases, but an average Chinese person is still responsible for only about 6 tonnes of emissions a year, compared to 25 tonnes for an average American.
One final thought: the UN model of consensual policy-making based on nation states doesn't work any more. If Copenhagen taught world leaders anything, it's that they need to work together in groups - geographical, economic, political - to define common positions ahead of global summits. (And no, it doesn't make much sense for China and India to be grouped together as "developing nations" with countries like Mali or Madagascar.)
Oh yes, and the EU needs to reflect on why it wasn't even included in that crucial 7pm get-together on Friday evening. Perhaps it was because Europe is already committed to emissions cuts far greater than anything that was under discussion in Copenhagen.
Or perhaps it's because in the eyes of Washington and Beijing, it simply doesn't matter as much as Brazil, India and South Africa.