What made US Marines urinate on Afghan bodies?

A video of US Marines apparently urinating on dead Afghans has caused controversy around the world, but US director and author Sebastian Junger says his experiences with soldiers in Afghanistan, meant he "kind of understood" what drove them to such actions.

The video, which was posted online, appears to show the troops standing over the bodies of several Afghans, at least one of whom is covered in blood.

Speaking to The Takeaway, a co-production with the BBC World Service, Mr Junger, author of "War" and co-director of the award-winning documentary "Restrepo", condemned the action, but said the soldiers had "been through a lot and it comes out in really weird ways".