So the whole of war, when you look at it is probably run by professional soldiers, and the rest of them are just recruits, or people who are just forced to join the army.
So, I created these creatures called The Frightened Ones which in the film you see do have mask like kind of heads and they run beneath the ground to hide. Which is what in fact we did during the war.
And when Roger talks about the frightened ones running away from the bombs, I immediately thought of my days when I was young and I had to wear these gas masks.