Cyberspace is regarded as an important area of protection for national security, so much so that many countries have now formulated strategies and policies on cybersecurity. This article focuses on the concept of “resilience,” a keyword emphasized in recent years as part of such strategies and policies. The article examines and analyzes its background and positioning from the standpoint of the theory of deterrence in international politics. The purpose of this paper is to demonstrate that the concept of resilience in cybersecurity has been adopted from discussions in other fields and is used from the national security viewpoint to deter aggressors.