PTSD: Returning to Afghanistan after the war
By the end of this month most US combat troops will have left Afghanistan and returned home - adding to the hundreds of thousands of veterans from Afghanistan and Iraq already back in the United States.
But for many of them, the real battles often begin on the home front. Twenty-two American military veterans are committing suicide every day, according to official government figures.
The BBC's Ian Pannell accompanied a group of veterans from both wars back to the frontline in Afghanistan. They are part of a unique programme to help veterans come to terms with their physical and mental injuries.
Filmed by Rob Magee and edited by John Landy