The Tallinn Manuals and the Making of the International Law on Cyber Operations



The Tallinn Manuals (the Manuals) attempted to clarify how to apply existing international law to cyber operations. Though the Manuals are non-binding instruments, the Group of International Experts claimed that they reflected the lex lata applicable to cyber operations. However, this claim is questionable due to the dominating role of a few Western states in the drafting process and the linked neglect of the practice of “affected states” in cyber operations. This article examines the quality of the Manuals’ drafting process and the composition and impartiality of the experts involved. It focuses on the issue of the prohibition of the use of force. The aim of this examination is not to discuss whether the Manuals provided the right answer to the question of how international law applies to cyber operations. Rather, they function as a case study of how legal scholarship may affect the making of international law. The article concludes that certain rules in the Manuals are marked by NATO influence and overlook the practice of other states engaged in cyber operations. Therefore, the Manuals disregard the generality of state practice, which should be the decisive factor in the formation of customary international law. As far as “political activism” may be involved, the article argues that the role of legal scholars as assistants to the cognition of international law could be compromised.

Cyber Attack; Cyber Operation; International Law-making; Legal Scholarship; Tallinn Manual

p. 67–86
Author biography

Papawadee Tanodomdej

Kyushu University

LL.D. Student, Faculty of Law, Kyushu University

[1] (2013) UN Doc A/68/98.

[2] Case Concerning Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v. Serbia and Montenegro). Judgement of 26 February 2007. ICJ Report 2007.

[3] Case Concerning Military and Paramilitary Activities in and Against Nicaragua (Nicaragua v. United States of America). Judgement of 27 June 1986. ICJ Report 1986.

[4] Case Concerning the Arrest Warrant of 11 April 2000 (Democratic Republic of Congo v. Belgium). The Joint Separate Opinion of Judge Higgins, Kooijmans and Buergenthal, Judgement of 14 February 2002. ICJ Reports 2002.

[5] D’Aspremont, J. (2016) Cyber Operations and International Law: An Interventionist Legal Thought. Journal of Conflict & Security Law, 21.

[6] Declaration of Judge Simma, Accordance with International Law of the Unilateral Declaration of Independence in Respect of Kosovo, Advisory Opinion, 22 July 2010, ICJ Reports 2010.

[7] Fleck, D. (2013) Searching for International Rules Applicable to Cyber Warfare – A Critical First Assessment of the New Tallinn Manual. Journal of Conflict and Security Law, 18.

[8] Greenwood, C. (1987) International Law and the United States, Air Operations Against Libya. West Virgina Law Review, 89.

[9] Kammerhofer, J. (2013) Lawmaking by scholars. In: Brölmann Catherine and Radi Yannick (eds.). Research Handbook on the Theory and Practice of International Lawmaking. Cheltenham: Edward Elgar.

[10] Kessler, O. and Werner, W. (2013) Expertise, Uncertainty, and International Law: A Study of the Tallinn Manual on Cyberwarfare. Leiden Journal of International Law, 26.

[11] Kingsbury, B. Krisch, N. and Stewart, R. (2005) The Emergence of Global Administrative Law. Law and Contemporary Problems, 68.

[12] Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory. Advisory Opinion of 9 July 2004, ICJ Reports 2004.

[13] Luhmann, N. (1993) Das Recht der Gesellschaft. Frankfurt: Suhrkamp.

[14] Lynn, W. J. (2011) Remarks on the Department of Defense Cyber Strategy as delivered by Deputy Secretary of Defense William J. Lynn. [speech] 14 July. Available from: [Accessed 12 July 2018].

[15] Mégret, F. (2005) From ‘Savage’ to ‘Unlawful Combatant’: A postcolonial Look at International Humanitarian Law’s Other. In: Anne Ordord (ed.). International Law and Its Others. Cambridge: Cambridge University Press.

[16] Parry, C. (1965) The Sources and Evidence of International Law. Manchester: Manchester University Press.

[17] Pauwelyn, J. (2012) Informal International Lawmaking: Framing the Concept and Research Questions. In: Joost Pauwelyn, Ramses Wessel and Jan Wouters (eds.). Informal International Lawmaking. Oxford: Oxford University Press.

[18] Reisman, M. (1981) International Lawmaking: A Process of Communication. American Society of International Law Proceedings, 75.

[19] Roscini, M. (2014) Cyber Operations and the Use of Force in International Law. Oxford: Oxford University Press.

[20] Schachter, O. (1977) The Invisible College of International Lawyers. Northwestern University Law Review, 72.

[21] Schmitt, M. (1998–1999) Computer Network Attacks: Thoughts on a Normative Framework. Columbia Journal of Transnational Law, 37.

[22] Schmitt, M. (2015) The Use of Cyber Force and International Law. In: Marc Weller (ed.). The Oxford Handbook of the Use of Force in International Law. Oxford: Oxford University Press.

[23] Skouteris, T. (2001) The Force of a Doctrine: Art. 38 of the PCIJ Statute and the Sources of International Law. In: Fleur Johns et al. (eds.). Events: The Force of International Law. New York: Routledge.

[24] Slaughter, A-M. (2000) Agencies on the Loose? Holding Government Networks Accountable. In: George Bermann and Peter Lindseth (eds.). Transatlantic Regulatory Cooperation, Legal Problems and Political Prospects. Oxford: Oxford University Press.

[25] Teubner, G. (1997) Global Bukowina: Legal Pluralism in the World Society. In: Global Law Without a State. Hants: Dartmount.

[26] The Tallinn Manual on the International Law Applicable to Cyber Warfare.

[27] The Tallinn Manual 2.0 on the International Law Applicable to Cyber Operation.

[28] Tikk, E. Kaska, K. and Vihul, L. (2010) International Cyber Incidents: Legal Considerations. Tallinn: NATO Cooperative Cyber Defence Centre of Excellence.

[29] Triggs, G. (2005) The Public International Lawyer and the Practice of International Law. Australian Yearbook of International Law, 24.

[30] US Naval War College. (2012) Cycon 2012 Michael Schmitt: Tallinn Manual Part I. [online video] Available from: (1:40) [Accessed 20 July 2018].

[31] Venzke, I. (2013) Contemporary Theories and International Law-making. In: Brölmann Catherine and Radi Yannick (eds.). Research Handbook on the Theory and Practice of International Lawmaking. Cheltenham: Edward Elgar.

[32] Waincymer, J. (2002) WTO Litigation: Procedural Aspects of Formal Dispute Settlement. London: Cameron May.





PDF views