Eight years into the war in Afghanistan, many fear it is unwinnable.
In response, the US-led international force has decided to adopt a counterinsurgency strategy, abandoning 40 years of military doctrine.
It emphasises security and development for the civilian population rather than simply battling the Taliban.
Lyse Doucet investigates if the US army can embrace a radical new strategy and will it deliver?
BBC Radio 4's Crossing Continents is broadcast on Thursday, 20 August, 2009 at 1102 BST and is repeated on Monday, 24 August, 2009 at 20:30 BST.
Reporter: Lyse Doucet
Producer: Colin Pereira