This paper discusses three approaches of what we call sovereignty and the protection thereof. The classical concept of sovereignty needs a multi-layered analysis in order to understand recent developments in different legal-political discourses and narratives. We suggest to take into consideration the following layers that are interconnected in various ways. The first aspect is the classical sovereignty concept of the 19th–20th centuries, which, after the consolidation of nation states, acts against attacks or interventions targeting the constituent elements and functions of the state (territory, population, legitimate government-jurisdiction). This model uses the mechanisms of the United Nations in addition to the classical nation-state defence and diplomatic instruments. Another layer notes the developments in Euro-Atlantic integration: recently we observe the sovereignty disputes within the European Union fuelled by the identity-discourse. The third dimension understanding sovereignty disputes is to characterise operations in cyberspace in the 21st century, targeting not only defence and critical infrastructure, but also democratic discourses. In this paper, we will review the main features of these sovereignty layers, with a particular focus on the lessons to be drawn from supranational and cyberspace disputes. The EU Member States’ toolbox, together with recent developments in sovereignty, identity and democracy protection, will be assessed in the light of European constitutional standards.