Walter Seymour Skinner, formerly known as Armin Tamzarian, is the interim principal of Springfield Elementary School, and a stereotypical educational bureaucrat. He struggles to control the crumbling school and is constantly engaged in a battle against its inadequate resources, apathetic and bitter teachers, and often rowdy and unenthusiastic students, Bart Simpson being a standout example. A strict disciplinarian, Skinner has an uptight, militaristic attitude that stems from his years in the United States Army as a Green Beret, which included service in the Vietnam War, where he achieved the rank of a sergeant, according to his rank insignia. As a result of his service in the Vietnam War, he is often plagued by horrible memories of his involvement via post-traumatic stress disorder, sometimes even happening at the most inopportune of times. It's also implied that he received a severe enough injury during the Vietnam War on his posterior to require a metal plate to be installed in it.