The conflict in Afghanistan risks becoming the "forgotten war" as the West's attention turns to events in Libya and the Middle East, David Miliband has warned.
The former foreign secretary predicted dire consequences in Afghanistan unless a "new level of urgency, coherence and effort" is put into reaching a political solution ahead of the planned withdrawal of UK and coalition military forces by the end of 2014.
Mr Miliband stressed the importance of talks with the Taliban, and even the possibility of offering concessions to get them to the negotiating table, in an effort to secure Afghanistan's future.
Ahead of a major speech at the Massachusetts Institute of Technology (MIT), Mr Miliband said: "The epochal events in the Middle East this year have redefined foreign policy.
"There are new priorities and challenges that need intensive Western engagement. But it is imperative that the war in Afghanistan does not become the 'forgotten war', as happened with such dangerous consequences after 2002."
Calling for intensive diplomatic and political activity to support the military effort, he said: "The 2014 end date set by Nato will prove illusory unless there is an end game.
"And that end game must be negotiations, involving Western powers led by the US, with all factions in the Afghan struggle, and their backers in the region."
Stressing the urgent need for progress he said: "Our leverage will decline, not improve, as 2014 approaches. The insurgency can spread, outstripping the ability of international and Afghan forces to check its growth.
"The warlords can strengthen their grip. Inter-ethnic strife can come to look more and more like civil war."
Mr Miliband said talks, under a UN-appointed mediator from the Muslim world, should take place in a "safe place" such as a Gulf state, Turkey or Japan.