There is growing interest in the future of Antarctic governance. For the last 60 years, the Antarctic Treaty System (ATS) has been comparatively successful in meeting its objectives, and sufficiently adaptive in the face of change. However, within the literature, there is increasing concern that, in the medium to long term, ATS responses to emerging geopolitical challenges may be inadequate. How do we assess this concern? How can organisations evaluate the future robustness of their current strategy? Antarctic futures have been explored within national Antarctic programs and they have been the subject of serious academic attention. Unfortunately, much of this commentary lacks a common language and analytical approach. To address this gap, we explore how the multi-disciplinary focus of classical geopolitics might be applied systematically to Antarctic scenarios. Here, we define geopolitics as the intersection between power, authority, and space, in rivalry between states. Over the course of this book, we illustrate a possible approach with the topical example of Antarctic militarisation. Along the way, we make suggestions to augment the current theory and practice of geopolitical scenario planning. We hope this work may be useful for those interested in the rigorous assessment of geopolitical futures-in Antarctica and beyond.