Cyberspace and the Transformation of Westphalian Sovereignty: a Theory-building Analysis

This article develops the Adaptive Sovereignty framework explaining how Westphalian sovereignty transforms in cyberspace. Introduction: The Peace of Westphalia (1648) established international order through territorial integrity, sovereign equality, non-intervention, and jurisdictional authority, yet cyberspace challenges these foundational principles through borderlessness, deterritorialisation, and attribution complexity. Objective: This study examines how cyberspace challenges and transforms Westphalian sovereignty, and what theoretical framework best explains observed adaptation patterns. Method: The study employs structured comparative case analysis of four illustrative cyber incidents (Estonia DDoS 2007, Stuxnet 2010, NotPetya 2017, and SolarWinds 2020) using process tracing and pattern analysis to identify conditional mechanisms determining state responses. Results: Rather than dissolution or persistence unchanged, sovereignty demonstrates institutional resilience through adaptive transformation: territorial control shifts to functional control; jurisdiction expands via effects-based principles; diplomatic practice evolves multilaterally through coordinated attribution mechanisms. Attribution confidence, disaggregated victim state power across four dimensions (economic, cyber-technical, diplomatic, normative), and geopolitical alignment jointly determine whether sovereignty violations generate targeted responses, norm entrepreneurship, or strategic silence. Conclusions: Integrating realist, liberal, constructivist, and postcolonial perspectives, this framework establishes how cyberspace creates neo-Westphalian order where traditional principles persist whilst operational modalities transform radically, extending historical institutionalism's layering and conversion mechanisms to sovereignty institutions.