A soldier's duty is to protect his country, and his job is never done. A horse's job is to protect his master, and his job is never done either. Throughout War Horse, Joey gets tasked with a variety of different jobs, from farming, to cavalry, to pulling heavy machinery. He never questions his orders, and he devotes 100% of his spirit and energy to getting things done right. You might be thinking, "Um, he's a horse," but that's exactly our point. His motivations might be different, but he has the same obligations in war as the human soldiers fighting alongside him.