There's a photo essay on My Modern Met of soldiers, Before, During and After combat.
There's the expected line in the blog about how we can see the shift in a person's psychology through portraiture, and specifically, through the shift in their facial features: cheeks sunken, weathered skin and small wounds.
The photographer in question, Lalage Snow, spent 4 years on and off with Brit soldiers in Afstan and Iraq and so I doubt that what she is doing subscribes to the "window to the soul" dialogue surrounding portraiture. I doubt it, because I don't think you come away from such experiences with that notion intact.
For myself, what's most interesting is that – likely – if you shift the order of the photos around, you would still read the images in order: Before, During, After. I also wonder about the role of the sitter, the soldier. In those moments before they sit in front of the camera, do they bring forward those months in the deserts of Helmand or the crumbling suburbs of Basra? Does the camera alter how your face fits together? Of course it does, and so for me, that's the worth of this series.
Everything I've typed above seems obvious, so let me add something else that's obvious: The decision of the photographer in choosing which photos to represent the soldiers. They exist in a place which seems part portrait studio, part photojournalism. The black background which creeps in around the edges is a curiosity and seems to remove them from context, from the war. By doing so we are allowed to focus only on the faces, but at the expense of the images seeming a bit too clinical, or staged.