This PhD thesis describes how Sweden can organise its offensive cyberspace capabilities for strategic objectives, including cyber deterrence and defence, in response to escalating threats from nations like Russia, China, and Iran. The research develops a multi-level and multi-domain (MLMD) theoretical framework, integrating deterrence theory, intelligence the- ory, and offensive cyberspace operations. Adopting an interpretivist research philosophy, the research employs a case study research strategy, reviewing scientific and military literature and conducting semi-structured interviews with key respondents in Swedish policy and defence. The findings suggest the need for a comprehensive national deterrence strategy encompassing offensive cyberspace capabilities, the operational organisation of cyberspace units supported by policy and intelligence, and a tactical emphasis on identifying and exploiting zero-day vulnerabilities. This research contributes to the field by offering models and frameworks for planning and executing offensive cyberspace operations, providing insights and increasing the knowledge base for professionals and researchers. Additionally, it advances the field by applying the MLMD framework for evaluating the research papers and using the general method for theory building in applied disciplines to assess the utility of the proposed model for offensive cyberspace operations.