Bunnies.

From the title, "The Wars" appears to be a book that discusses upon not just physical war, but war of all sorts, as evident by the diction in the title, as war is presented in its plural form, wars.  For the first time within the novel, my presumption has been agreed with.  The concept of eradicating the rabbits, which embody the protagonist's passion for his sister, as well as the mental conflict of performing an act of murder delves upon both the physical and metaphysical aspects that come with war and violence.  The protagonist Robert Ross, ponders upon the justification for commiting such an action, much like an emotionally capable soldier would ponder initially on the brink of battle. I believe that this concept will be further exemplified throughout this novel.