Book excerpt: Survival, the IISS’s bimonthly journal, challenges conventional wisdom and brings fresh, often controversial, perspectives on strategic issues of the moment. In this issue: Nigel Gould-Davies assesses the impact of Western sanctions on Russia, arguing that they represent a major development in economic statecraft In a special colloquium on the North Korean nuclear threat, Jina Kim, John K. Warden, Adam Mount, Mira Rapp-Hooper, Vipin Narang, Ankit Panda, Ian Campbell and Michaela Dodge offer their ideas for deterring Pyongyang Alexander Klimburg warns that CYBERCOM’s strategy of ‘persistent engagement’ is encouraging a cyber arms race And eight more thought-provoking pieces, as well as our regular book reviews and noteworthy column