KEY POINTS:
When George W. Bush first met Angela Merkel, shortly after she became Chancellor of Germany 18 months ago, he thought he had finally found a friend from "Old Europe".
Believing the right-wing former East German would be far less interested in the environment than the red-green government she had toppled, he patronisingly suggested they could forget the Kyoto Protocol.
"Mr President, you are mistaken," Merkel announced, drawing herself up to her full 1.7m. "I am one of those responsible for the protocol."
And she told him how, as her country's Environment Minister, she had chaired the meeting that had made the crucial breakthrough on the road to Kyoto, and then led its negotiating team when the treaty was agreed.
Over the past six months, the embattled President has had plenty of opportunity to remember his faux pas. For the Chancellor - the youngest person, as well as the first woman - to hold the office, has constantly harried him to drop his obstruction to negotiating new international measures through the United Nations for when the protocol's targets expire in 2012.
Indeed, she has formed a double act with British Prime Minister Tony Blair. Between them they recruited a formidable team of allies including European Union President Jose Manuel Barroso, Japanese Prime Minister Shinzo Abe, French President Nicolas Sarkozy and even Rupert Murdoch - and joined forces with the Republican governors led by Arnold Schwarzenegger, congressional and business leaders, and even leaders of the religious right putting pressure on Bush at home.
The object of the campaign was to get Bush to give enough ground at last week's G8 summit in Heiligendamm, on the German Baltic coast, to make possible a breakthrough in the UN negotiations this year. It helped to make it one of the most cliff-hanging G8 summits ever.
Once it was possible to sum one up before it even began, as the final communique would have been settled in advance, and the media swarm would have to scratch about in the "bilaterals", the one-on-one side meetings among the leaders of the world's seven largest industrialised economies, plus Russia, to find something to report. Not this year.
There was no previous agreement on the central topic of climate change. At the same time, activists, development organisations - and singers turned campaigners Bono and Bob Geldof - wanted Blair to confront fellow summiteers over the targets they agreed at Gleneagles two years ago for aid to Africa.
And on the very eve of the gathering, there suddenly flared up a dispute between Russia and the West which appeared to threaten a return to the Cold War.
It all got hammered out eventually with a bland communique - but not without some dramas. The biggest was over climate change, when - just a few days before the leaders met - Bush tried to derail the UN negotiations by proposing a series of American-led talks among the world's top polluters with no more demanding a goal than vaguely aiming at agreeing on a series of non-binding measures.
This spoiling tactic had been in preparation for months, with one of the President's top climate hatchet men, James Connaughton, circling the globe trying to persuade other countries to sign up for it.
And Blair made things worse by appearing enthusiastically to endorse it.
But by the time the summiteers headed home on Friday evening, Bush appeared to have lost on points. His sabotage attempt had been largely defused and he had been forced to cross several of his negotiating "red lines".
And Blair and Merkel, though unable to achieve their stated objectives, had not had to cross "red lines of their own", and managed to maintain forward momentum towards a new climate change agreement.
Not that this is obvious from the communique. The original German draft pledged to cut emissions of greenhouse gases by half over 1990 levels by 2050, so as to keep global warming to an extra 2C - and called for a 20 per cent increase in energy efficiency by 2020 and "cap and trade" programmes (national allowances of greenhouse gas emissions which can be bought and sold).
None of this should have been contentious. The 2C limit is the least scientists say will be necessary to avoid climate change escalating out of control: the 50 per cent cut is what is needed to meet it.
The energy efficiency target is easily achievable with existing technology, and cap and trade was an American invention in the first place. But Bush set his face against them. All that appears in the communique is a vague reference to cap and trade and a curious and apparently meaningless construction under which the leaders agree to "consider seriously the decisions made by the European Union, Canada and Japan which include at least a halving of global emissions by 2050".
Thus far it looks as if Bush won. But, in fact, he was forced to cross red lines in agreeing to any mention whatsoever of the 50 per cent cut or to cap and trade measures. And he was forced to give even more, previously unsurrenderable, ground, by accepting that climate negotiations should proceed through the UN with an agreement reached by 2009.
It took a huge effort by an alliance of Merkel, Blair and Sarkozy to achieve even this much. Merkel went first, getting him to scale down his diversionary plans and to accept that negotiations should continue through the UN. She then handed over to Blair and Sarkozy, who discussed tactics and then jointly nobbled Bush. The final act was played out the next day when Blair and Bush worked out the wording on the 50 per cent cut.
It all seemed too much for Bush to stomach; he failed to attend the first session the next morning with a tummy upset. But he emerged to meet the leaders of China, India, Brazil, South Africa and Mexico - also invited to the summit - and tell them that he was committed to taking action on climate change.
Set aside the desperate need for rapid action to bring global warming under control - or the Merkel-Blair campaign - and such progress is pretty pathetic.
But compared with Bush's previous position it is dramatic. Not long ago he was resisting even holding talks about new negotiations on climate change. The momentum is also now against him, and his presidency does not have long to run.
Much now depends on whether Gordon Brown takes up the baton. So far he has shown little of Blair's commitment to a global deal, but he has been moving in that direction. He has promised to keep up the pressure on Bush and is considering plans for a beefed-up climate change unit at the heart of Government, in the Cabinet Office.
The plight of Africa has long been close to his heart, and here again the summit hovered between triumph and disaster.
Two years ago, at Gleneagles, the leaders agreed to increase aid by US$50 billion ($66 billion) a year by 2010. Some countries, including Britain, are on track to achieving this, but others - notably Italy and Canada - are falling behind and the target looks as if it will be missed by a full US$22 billion.
But Blair, Merkel - and, perhaps surprisingly, Bush - all put pressure on the laggards, and the slack could possibly yet be made up over the next three years.
The summit began with superpower tensions reminiscent of the Cold War. Russia has long muttered angrily about American plans to station elements of its missile shield in the Czech Republic and Poland and, shortly before going to Heiligendamm, Putin threatened to target Russian nuclear weapons at Europe if the US sited its radars and interceptors there.
Bush insisted the system was purely defensive, aimed not at Russia but at maverick states such as Iran and North Korea.
Visiting the Czech Republic on his way to the summit, he said the missile system was "not something we should hyperventilate about" - in fact, Russia should join in its development.
He added a blunter message on the Kremlin's internal policies.
"In Russia," said Bush, "reforms that once promised to empower citizens have been derailed, with troubling implications for democratic development."
But the expected showdown never happened. Putin apparently sought to catch Bush off-balance with a call for the US to base its missile defences in Azerbaijan, an offer Bush said he would consider.
So no new Cold War, but the impression of the Russian leader as prickly and impulsive, with an authoritarian streak many metres wide, will linger.
Of course, G8 summits can be as significant for what is not discussed as for what is. Despite the focus on Africa, there was only cursory attention given to the humanitarian crisis in Darfur. Russia stood firm against pushing through a deal on Kosovo's final status without Serbian agreement And not a public word was uttered on Iraq.
As ever, commentary on this year's gathering is awash in oceans of rhetoric. If it were a school report, a dispassionate verdict would read: "Progress made. Could do better."
- INDEPENDENT
