It was dubbed "the most expensive 72 hours in Canada's history" – two international summits for 20 world leaders, a few other invited prime ministers and several gatecrashers, at an estimated cost of £645m.
After his debut on the global stage in Toronto at the weekend, David Cameron is already planning to halt the "travelling circus" summits for the presidents and prime ministers of the eight leading economies when Britain takes its turn as G8 president in 2013.
Mr Cameron wants the G8 to revert to the "fireside chats" with which the United States, Britain, France, Germany, Italy and Japan began their annual meetings in 1975. Canada and Russia were allowed in later.
Security was heightened to protect the leaders from anti-capitalist protesters as they enjoyed their fine food and wine, adding to the impression that they were remote from the people who had elected them. The absence of fast-growing China and India exposed the group's weakness but it took the 2008 financial crisis to bring matters to a head.
The G20, including emerging economies, has now eclipsed the G8. The wider group prevented recession from turning to depression through a co-ordinated fiscal stimulus; its London summit last year was the high point of Gordon Brown's premiership. But that was when everyone agreed on what to do. In Toronto at the weekend, the G20 could only agree to disagree on the pace at which the stimulus should be replaced by cutting budget deficits.
The G20's 10,700-word communiqué was a fudge: all things to allow all the leaders to tell their domestic audiences they had won the day. Their aides fed favourable titbits to a ravenous media before the statement was signed off by the leaders – an old trick. This time, the British spin was based on substance. Last week's Budget has definitely got noticed. We're not any good in the World Cup but we are top of the austerity league now that spending cuts are in fashion. Mr Cameron and George Osborne won plaudits, even though the Obama administration is worried that Europe is cutting too soon.
The US president has a point: if everyone cuts to calm the markets, where is the growth going to come from? The deficit hawks reply that there will be no growth without confidence in the markets, unnerved by Greece's debt crisis.
Mr Cameron believes G8 meetings should be combined with another international summit – perhaps a Nato or UN gathering – to keep down the cost. Although some observers believe the G8's days are numbered, the Prime Minister thinks it still has a useful role in hosting informal discussions on foreign policy and security issues such as Afghanistan, Iran and the Middle East.
He also wants the "rich nations' club" to keep providing aid to the poorest countries. If that was its main focus, he believes, it would be more likely to keep its promises – scandalously, it has failed to do so on the historic pledge to double annual aid to $50bn (£33bn) by this year.
As the newest leader in the G8 bloc, Mr Cameron is not trying to dictate the club rules. Other leaders will have other ideas and Nicolas Sarkozy certainly does.
France holds both the G8 and G20 presidencies next year and, although the hyperactive French president is promising the cost will be "10 times less" than Canada's long weekend, he will not adopt the low-key approach planned by Mr Cameron. Stand by for the Year of Sarko.
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