It's not really about war as in the physical sense of fighting, but rather, emotional war. He was popular last time and 'ruled the world', ut now he is experiencing rejection. The 'mirror, sword and shield' are actually referring to the help that he needs. The 'mirror' is his reflection on what he had done wrong, the 'sword and shield' is for him to 'fight and defend' himself when he seeks forgiveness from his friends. There are still people out there who are jealous of him and wants to see him defeated. This song is more about rejection and depression, not war and fighting, in my opinion. :)