The son cannot help the mother in grief. He can only observe his anguish and wait for time to pass and healing to begin. It hurts the son to see his mother, who is so strong, become so dejected and apathetic towards life and the war going on in their country. Bomber planes are notoriously noisy. The fact that she doesn't even look up at the sky when a bomber passes shows how dejected she is. She is so deeply discouraged that she doesn't even want to go to the cellar to protect herself. Could the mother be grieving the loss of her eldest son? This son was reportedly recently killed in the war and the mother believes in the cause of the war. So he won't speak badly of the war. The younger son may feel guilty because he is alive and his brother is dead. He is unable to fill the void of losing his mother. His brother dies a hero but so does a part of his mother