The BBC's Ian Pannell accompanied a group of US veterans back to the frontline in Afghanistan. They are part of a unique programme to help them come to terms with their physical and mental injuries. Subscribe to BBC News HERE bit.ly/1rbfUog Check out our website: www.bbc.com/news Facebook: www.facebook.com/bbcworldnews Twitter: www.twitter.com/bbcworld Instagram: instagram.com/bbcnews