Following the UK defence secretary’s announcement in September 2018 that the Ministry of Defence is to devise a Defence Arctic Strategy, Duncan Depledge, Klaus Dodds and Caroline Kennedy-Pipe look back on how UK defence has engaged with the Arctic over the past two decades and draw attention to the shift in focus from climate change to hard security threats. They analyse what this means for the development of national Arctic policy in general, including the potential for divergence with other stakeholders such as the Foreign Office and the Scottish government. They conclude by considering how UK Arctic policy might change after Brexit.