Cyberattacks are one of the greatest fears for both governments and the private sector. The attacks come without warning and can be extremely costly and embarrassing. Robert Mandel offers a unique and comprehensive strategic vision for how governments, in partnership with the private sector, can deter cyberattacks from both nonstate and state actors. Cyberdeterrence must be different from conventional military or nuclear deterrence, which are mainly based on dissuading an attack by forcing the aggressor to face unacceptable costs. In the cyber realm, where attributing a specific attack to a specific actor is extremely difficult, conventional deterrence principles are not enough. Mandel says that cyberdeterrence must alter a potential attacker's decision calculus by not only raising costs for the attacker but also by limiting the prospects for gain. Cyberdeterrence must also involve public-private partnerships, cross-domain responses must be considered, not just retaliation in kind. The book includes twelve twenty-first century cyberattack case studies in order to draw insights into cyberdeterrence and determine the conditions under which it works most effectively. Mandel concludes by making recommendations for implementing cyberdeterrence and integrating it into broader national security policy.