US soldiers train in the staged Iraqi village in Fort Irwin, California.
Deep in the California desert lies Fort Irwin, a vast US military base.
It's home to something extraordinary: Medina Wasl, one of a network of 12 or so mock Iraqi villages, built by the US Army at a cost of many millions of dollars.
The villages form part of the setting for a war game simulation on an epic scale.
Hundreds of Arabic-speaking Americans have been hired to play the part of Iraqi villagers.
Mingled amongst them are Special Forces soldiers, who take on the role of insurgents and try to kill as many US soldier trainees as possible in elaborately staged war games.
A third of US troops now in Iraq have been trained here or at similar facilities. The trainees face mortar attacks, riots, kidnappings, booby-trapped dead dogs, suicide bombings and even staged beheadings in underground tunnels.
Army trainers act as referees to decide who has been killed or wounded. The insurgents usually win. Instructors are assisted by Hollywood actors and stuntmen.
The training is so realistic some soldiers have suffered battle fatigue.
What's taking place at Fort Irwin lies at the heart of a vast shift in American military strategy, one of the biggest changes in 50 years, with a new emphasis on nation-building and peacekeeping.
The aim of the training is not just to lower the death toll amongst soldiers and civilians - it's also about gaining the trust of local populations.
Peter Day tells the extraordinary story of Medina Wasl.First broadcast on 18 August 2008