The threat of military strikes on Afghanistan is intensifying a refugee crisis caused by years of famine and intolerance. There are 3.7m Afghan refugees - the biggest group of dispossessed from any country in the world.
BBC News Online looks at the scale of the crisis and the international response to the problem.
The battle for food
Refugees wait for food at an Afghan camp
As winter approaches, the threat of famine hangs over millions of refugees in Afghanistan. International aid agencies have been working to help the thousands of people who are fleeing the region and to get food to those who stay.
Christian Aid's Dominic Nutt has been working in Afghanistan
Millions of refugees depend on food handouts to survive, but with very little aid getting into Afghanistan neighbouring countries risk being swamped. Relief organisations and the United Nations have appealed for urgent help to stave off a catastrophe.
Pakistan is already hosting 2.2m Afghan refugees
Click here for Adam Brookes' report
Tajikistan enters equation
As Afghans continue to flee in fear of war, thousands of refugees are heading for the border with Tajikistan. However, the former Soviet republic is refusing to let them in because it is struggling to cope with a crisis of its own - widespread hunger caused by a drought.
One million Tajiks are threatened with starvation
Click here for David Shukman's report
Long lasting humanitarian crisis
The attacks on America have brought the plight of Afghan refugees to the world's attention, but the problem dates back several years. In February the BBC's Matt Frei was allowed deep into Afghanistan to see conditions at the Herat camp in the west of the country.
Afgan crisis: Aid needed for months
Click here for Matt Frei's report
The international response
With the basic priorities of food, water, sanitation and shelter at the forefront of helping the Afghan refugees, international agencies are calling for a governmental coalition to provide the safe and effective distribution of aid. Oxfam is pleased with the response so far.
A 'coherent' approach is needed by all parties
Oxfam's director for Afghanistan John Fairhurst
A new alliance forms
In additon to the global coalition against terrorism, 15 countries met in Berlin to plan the wider relief effort for refugees. UN Secretary General Kofi Annan called for the international community to provide $584m for the projected needs of up to 7.5m Afghans over the next six months.
Annan says money may not be enough
Click here for Emil Petrie's report
UK pledges additional financial support
The UK government has given an extra £11m to help Pakistan deal with a flood of refugees from neighbouring Afghanistan. The extra money comes on top of the £25m which had already been earmarked when the scale of the crisis in Afghanistan first became clear.
Clare Short has lobbied hard for financial aid
UK International Development Secretary, Clare Short