Who is The Veteran, August Wiener from The Forgotten Soldier and what is their importance?

Sajer first meets the Veteran on the Belgorod front where they are assigned to the same assault unit. The Veteran described as experienced..... a man with attuned sense of self-preservation. He speaks Russian, shares an easy camaraderie with Hauptmann Wesreidau, and he is blunt in his opinions about the war.... something that shocks Sajer. In the end, the Veteran sacrifices his own life for his comrades when he holds a machine gun position that allows his fellow soldiers, include Sajer, to successfully retreat.