First things first, Halo rules!!
It's obviously my inspiration for this one... But secondly, it's the idea that when it comes down to it, fighting is a deeply personal thing. It's a harsh thing to think about and reflect on. So I'm portraying this soldier taking a step back, while he can, to take it all in. The Uncle Sam poster on the wall does in no way indicate that the soldier is American, but does indicate the continuous 'want' for military defense, in any country, or on any planet for that matter.