Obama left Washington late Thursday with the two-week Copenhagen conference on a knife-edge, facing a stiff test of his diplomatic mettle, amid warnings of a looming “catastrophe” in Denmark.
“The president will be coming to the most complicated, complex, international meeting that he has seen as president,” said a senior US official on condition of anonymity.
“He will be very well positioned to have an impact here,” the official said, but admitted: “I do not know what the outcome will be at the end.”
Constrained by the delicate domestic politics of climate change back home, Obama faces high expectations here.
The United States is pushing for an “operational agreement” to pave the way for a binding treaty on cutting carbon emissions next year — which would have more teeth than a flurry of mere pledges of future action by nations.
Some leaders appear to harbour hopes the American president will unpick a deadlock between developed and developing states.
“As far as I know he’s coming here to show leadership — what everybody expects from the United States of America and from President Obama himself,” said European Commission chief Jose Manuel Barroso.
But exactly what Obama can offer is uncertain.
Washington has already said it will not budge on its offer of curbing US carbon emissions by 17 percent from 2005 levels by 2020 — less than EU offers but as much as the US political climate will bear.
Secretary of State Hillary Clinton said Thursday Washington would pay into a fund worth 100 billion dollars a year by 2020 to help poor countries cope with climate change, but left the exact figure unspoken.
Officials warned Obama will likely steer clear of specifics when he addresses world leaders here on Friday.
Generally, US presidents prefer to wager their prestige only when a major foreign policy win is already locked in, to avoid the sting of coming home empty-handed.
Yet Obama headed to Copenhagen for the second time within three months, hazarding big chunks of personal political clout with a favorable outcome for his mission up in the air.
Denmark stirs rotten memories inside the White House.
In October, Obama flew into political embarrassment, when the International Olympic Committee snubbed his bid to secure the 2016 summer Games for Chicago.
It was a political goldmine for domestic foes who think the world sees Obama as a soft touch.
The White House Thursday appeared to be rolling out the first steps of a damage control operation, as the mood turned dark in Denmark.
“Coming back with an empty agreement would be far worse than coming back empty handed,” said Obama spokesman Robert Gibbs.
Clinton meanwhile accused developing nations, apparently with an eye on China, of backsliding on transparency requirements designed to prove they live up to promised emission cuts.
“If there is not even a commitment to pursue transparency, that’s kind of a deal breaker for us,” Clinton said. It was not clear if she was playing the “bad cop,” or preparing a face-saving exit for her boss.
The climate conference is the latest international crisis in the president’s frenetic first year in power — including the worsening Afghan war, Iran’s nuclear gauntlet and the economic meltdown.
In Copenhagen, a familiar scenario is unfolding, with Obama balancing his multilateral global engagement with a vulnerable political front back home as isolationist sentiment rises.
US sceptics warn a domestic cap-and-trade plan to cut emissions logjammed in the Senate will strangle the nascent economic recovery.
At the same time, Obama’s bargaining position in Copenhagen and the hopes of the summit themselves are hampered by Senate foot-dragging, and the lack of a new US global warming law limits Obama’s capacity to compromise in Copenhagen.
But should he go home with no deal, prospects for Congressional action on the cap and trade bill will absorb a huge blow.
Opponents of Obama’s plans to rein in US emissions will ask why should Washington accept punishing hits to its own economy if its major developing rivals like China and India will not also pay a price?