There are concerns over future food shortages in Afghanistan
An emergency relief operation is needed to prevent progress in Afghanistan being undermined by a devastating famine, a UK think tank has warned.
The Royal United Services Institute (Rusi) says food shortages represent a greater threat than the Taleban.
It is calling for the international community to mount a smaller repeat of the Berlin Airlift during the Soviet blockade of west Berlin in 1948.
Rusi says action was needed before the winter but required "political will".
A humanitarian disaster threatened the Afghan government and the United Nations-mandated mission in the country, it added in a briefing note.
A combination of light spring rains, a summer drought, poor irrigation, low crop yields in the north and north-west of the country and rising world food prices is said to have left a third of Afghans - an estimated 8.4 million people - facing possible famine.
The United Nations World Food Programme estimates the country will need 25,000 metric tonnes of food aid by the winter and an additional 70,000 tonnes by February.
In the briefing note, Rusi said: "Rapidly transporting 25,000 tonnes of foodstuffs into Afghanistan should be well within the international community's military capacity if - it has the will."
Paul Smyth, head of the Rusi's operational studies programme and the briefing note's author, told the BBC that with "concerted efforts" an airlift could take place over a period of about three to four weeks in November and December.
He said: "It's only the global military which has the capacity and capability to take the necessary action before deterioration in the weather."
Rusi suggested that those nations not involved military in Afghanistan could contribute financially or transport aid to regional hubs.
From there, supplies could be flown into Afghanistan by those with air capability, such as the US. Airlifts would also be needed to deliver aid to isolated communities.
Rusi said the Afghan population would turn increasingly to the international forces in the country for help once winter sets in.
"Afghanistan may be on the brink of a calamity which has the potential to undermine much of the progress which has been achieved there, especially in areas ostensibly free of insurgent activity," it added.
The paper said: "Exactly 60 years ago, the Berlin Airlift was under way.
Rusi said a famine could threaten the progress in rebuilding the country
"It brought food to millions and prevented a strategic defeat. Today, a much smaller, yet strategically significant operation could have similar effect in Afghanistan."
Rusi said there was now a "window of opportunity" to act before the weather conditions for flying deteriorated, and said failure to take effective action would damage the "credibility and moral authority" of the international community in Afghanistan.
It said: "Afghanistan may be on the brink of a calamity which has the potential to undermine much of the progress which has been achieved there, especially in areas ostensibly free of insurgent activity.
"If the international community is found wanting, we can expect increasing frustration and anger from a population which once saw the international intervention in Afghanistan as a source of hope."
A spokeswoman for the Department for International Development said: "This year alone, Dfid has contributed £16.5m to alleviate the food shortages in Afghanistan.
"We believe that the best way to deal with the humanitarian situation in Afghanistan is through the recovery voucher scheme which supports farmers in drought-affected provinces in the north and north-west of the country.
"This is designed to increase the purchasing power of poor farmers to ensure that they are able to purchase agricultural inputs including seeds, fertilisers and tools."