War metaphors are ubiquitous in discussions of everything from political campaigns to battles with cancer to wars against crime, drugs, poverty, and even salad. Why are warfare metaphors so common, and what are the potential benefits and costs to using them to frame important social and political issues? We address these questions in a detailed case study by reviewing the empirical literature on the subject and by advancing our own theoretical account of the structure and function of war metaphors in (...) public discourse. We argue that war metaphors are omnipresent because they draw on basic and widely shared schematic knowledge that efficiently structures our ability to reason and communicate about many different types of situations, and they reliably express an urgent, negatively valenced emotional tone that captures attention and motivates action. Nevertheless, we find that the meaning of war metaphors is intimately tied to the context in which they are used, which may result in either positive or negative outcomes, depending on the situation. Thus, blanket statements about whether or not a war frame is useful are misguided or overly constraining. Here we situate our case study results in relation to popular theories of metaphoric representation and processing and offer some guidelines for using a war framing effectively. This work helps illuminate the complex, dynamic, and nuanced functions of metaphor in cognition in general, and in public discourse in particular. (shrink)