The Tallinn Manual

by JIMz

2 min read


The Tallinn Manual, formally titled "Tallinn Manual on the International Law Applicable to Cyber Warfare," is a significant document in the realm of cybersecurity law. Here's a detailed breakdown of its key aspects:

Origin and Purpose

  • Authored by a group of international law experts between 2009 and 2012.
  • Commissioned by the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) located in Tallinn, Estonia. (Though it's not an official NATO document.)
  • Aims to clarify how existing international law applies to cyber conflicts and cyber warfare.
  • Focuses on two key areas of international law:
    • Jus ad bellum: Rules governing the use of force between states.
    • International humanitarian law (jus in bello): Rules applicable during armed conflicts to protect civilians and combatants.

Content and Structure

  • Not a binding legal document, but a highly influential academic study.
  • Comprises two editions:
    • Tallinn Manual (2013): Examines the most severe cyber operations, including those that could constitute a use of force or occur during armed conflicts.
    • Tallinn Manual 2.0 (2017): Addresses the legal framework for less severe cyber incidents that fall below the thresholds mentioned above.
  • Structured around 95 "black letter rules" that interpret how existing international law principles apply to specific cyber scenarios.
  • These rules address various topics like:
    • Sovereignty in cyberspace
    • State responsibility for cyberattacks
    • Targeting civilians and civilian infrastructure in cyber operations
    • Proportionality and distinction in cyber warfare

Significance and Impact

  • Considered a foundational text in the field of cyber law.
  • Provides a framework for states to assess the legality of their cyber operations and those they face.
  • Influences legal discussions and policy decisions regarding cyber issues at the international level.
  • Serves as a reference point for ongoing efforts to develop new international law norms specifically for cyberspace.


  • Being non-binding, it cannot definitively resolve legal disputes.
  • The evolving nature of cyber technology may necessitate future updates and interpretations.
  • Controversial topics, such as cyber espionage or the use of force in cyberspace, may have varying interpretations among states.


Overall, the Tallinn Manual is a crucial resource for understanding how international law applies to cyber conflicts. It has significantly shaped the discourse on cybersecurity law and continues to influence efforts to establish a more robust legal framework for this complex domain.