By David Loyn
World affairs correspondent, BBC News
The talks come days after Mr Obama announced his new Afghan strategy
Delegates from 70 nations are gathering in The Hague to discuss reconstruction in Afghanistan, against the new backdrop of the major Obama strategy for the country unveiled last Friday.
President Barack Obama wants a modest increase in US troops, many more civilian advisers, and is hoping to engage wider regional support to improve security in Afghanistan.
The Hague meeting could see the first moves towards high-level contact between the US and Iran since the Islamic revolution of 1979 brought the Ayatollah Khomeini to power.
If it goes well, there is even speculation that the US will ask Iran if non-military equipment for Nato forces could be allowed to cross Iran.
'Investment for the world'
Afghan President Hamid Karzai will head a large team from Kabul, and his ambassador in the US, Said Jawad, made a passionate appeal that the world should not forget Afghanistan as it has done before.
At a pre-conference meeting, organised by The Hague Centre for Strategic Studies, he said: "Being in Afghanistan is dangerous, but not being in Afghanistan is a lot more dangerous, and we learnt this on 9/11.
"Being in Afghanistan is an investment for your children, for the future of Afghanistan and the world."
The political system that is emerging in Afghanistan may not have the most rigorous democratic standards, but the Bush years of believing that countries could be fixed by imposing a voting system from outside are over.
Said Jawad said there were other tests of democracy.
"If democracy means not fearing the secret police, having the opportunity to send your daughter to school, or the opportunity to give birth as a woman without fearing death - this is the right of every human being," he said.
"This is what every Afghan deserves and demands."
Although this conference will not make specific demands for cash, the need to raise more money is at the heart of the negotiations.
And a wider regional strategy demands that the money be raised more widely.
Nato's leader says nations that have not sent troops should help with funds
Afghanistan needs funds in particular to pay for its larger armed force. For now international support for that raises $25m (£17.5m), far short of the requirement for $2bn a year.
Nato Secretary-General Jaap de Hoop Scheffer said it would be "impossible" for Nato countries to find that money.
In an interview with the Financial Times before the conference, he said that other nations such as Japan, the Gulf States and Saudi Arabia should shoulder more of the burden.
"It is difficult to see how Nato allies, given the enormous amount they are spending keeping forces there, can bring in $2bn a year," he said.
But while policymakers in America and the UN all agree that mistakes have been made since 2001, they do not yet agree how they can improve the situation.
The biggest challenge to the new initiative is that Afghanistan's regional neighbours - Iran, China, the Central Asian republics, India and Pakistan - do not share goodwill for US success in Afghanistan.
The meeting of most of these countries in Moscow last Friday, under the aegis of the Shanghai Co-operation Organisation, could end up a far more important forum for international agreement on Afghanistan, where the West plays a far smaller role.
But for now the American initiative is dominating the agenda, and this conference has concrete goals.
The head of the UN mission in Afghanistan, Kai Eide, said that there had been "fatigue" in the international community.
"We have not been as good as we should have been," he said.
With better co-ordination and more realistic goals, progress can be achieved, he said, but no-one here thinks that peace in Afghanistan will come easily.