Cyberspace is often described as the fifth domain of military operations, as equally critical to national and international defense as the domains of land, sea, air, and space. The success of military missions increasingly depends on the availability of cyberspace and freedom of action in it. Robust and resilient cyber defense capabilities are now required to support military structures, missions, and operations. Because of severe budget constraints and scarce resources, leaders see NATO’s Smart Defence and the European Union’s pooling and sharing efforts as pragmatic and coherent ways to generate the cyber defense capabilities. NATO member nations and EU member states need to face future challenges. As this work moves forward, cyber remains a dual-use sector that offers many opportunities to develop synergies covering several aspects of cyber defense and security, from competence profiles to research and development.