He's wrong, an asshole, and harasses and even beats up elderly veterans trying to get the truth from them. He's right, too. War is hell. Look what it did - to his dead comrades, to his fellow veterans, to him. He's obsessed, crazy, driven, desperate, sociopathological. Ultimately (not in the movie) he tries to kill his superior from the war, who he holds most immediately responsible for the deaths of his comrades. He can't find him and settles on shooting his son instead - and is sentenced to hard labor.
I strongly appreciated that he held the Emperor ultimately accountable for the deaths of his comrades, and for all the suffering of the war.