Skip to main content

The Applicability of Article 51 UN Charter to Asymmetric Wars

  • Chapter
From Cold War to Cyber War
  • 2947 Accesses


Resolution 1368 of 12 September 2001 qualified international terrorism as a ‘threat to the peace’, and emphasized at the same time the ‘inherent right to individual and collective self-defence’ with regard to such acts. As a consequence, the question arose whether this resolution was a watershed allowing the recourse to article 51 of the UN Charter in cases of terrorism. The subsequent practice is inconclusive in this regard as the State community has been extremely reluctant to extend the purview of the right to self-defence to attacks by Non-State actors. In view of these legal uncertainties academics and members of civil society have sought to provide greater clarity on the topic. The ‘Chatham House Principles of International Law on the Use of Force by States in Self Defence’ of 2005, the ‘Leiden Policy Recommendations on Counter-Terrorism and International Law’ of 2010 and the ‘Principles on Self-Defence against an Imminent or Actual Armed Attack by Non-State Actors’ presented by Daniel Bethlehem in 2012, while not fully coincident, as a whole convincingly argue for a more extensive interpretation of article 51 of the UN Charter that would allow the countering of international terrorism more effectively.

Dr. Peter Hilpold is Professor for International Law, Law of the European Union and Comparative Public Law at the University of Innsbruck.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
USD 84.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 109.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 109.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Similar content being viewed by others


  1. 1.

    See generally on asymmetric wars, W. Heintschel von Heinegg, Asymmetric Warfare, 2010, in: Max Planck Encyclopedia of Public International Law, at (all accessed on 14 November 2014).

  2. 2.

    K. Annan, In Larger Freedom. Towards Development, Security and Human Rights for All, Report of the Secretary-General, UN Doc. A/59/2005, para. 91; on this report as well as on the various attempts to define terrorism see P. Hilpold, Reforming the United Nations: New Proposals in a Long-Lasting Endeavour, in: Netherlands International Law Review 52 (2005), pp. 389–431; UN Doc. A/Res/60/288; on the various attempts to define terrorism in international law, see C. Walter, Terrorism, in: Max Planck Encyclopedia of Public International Law, at

  3. 3.

    See H. Kelsen, The Law of the United Nations, London 1950, p. 791.

  4. 4.

    See A. Bianchi, The International Regulation of the Use of Force: the Politics of Interpretative Method, in: L. van den Herik/N. Schrijver (eds.), Counter-Terrorism Strategies in a Fragmented International Legal Order, Cambridge 2013, pp. 283–316, at p. 301 referring to ICJ, Armed Activities in the Territory of the Congo, Judgment of 19 December 2005. See on this judgment R. Uerpman-Wittzack, Armed Activities on the Territory of the Congo Cases, in: Max Planck Encyclopedia of Public International Law, at

  5. 5.

    See A. Cassese, Terrorism is also Disrupting some Crucial Legal Categories of International Law, in: 12 European Journal of International Law (2001), pp. 993–1001 (996) and C. Stahn, Nicaragua is Dead, Long Live Nicaragua – the Right to Self-defence Under Art. 51 UN Charter and International Terrorism, in: C. Walter et al. (eds.), Terrorism as a Challenge for National and International Law: Security Versus Liberty?, Berlin 2004, pp. 827–877 (832). National Courts were more likely to accept the contention that asymmetric conflicts by their country’s government against insurgents, often characterized as terrorists, were to be qualified as “armed conflicts”. This was the case for Peru’s National Criminal Chamber as to the Shining Path, the US Supreme Court with regard to Al Qaeda (in Hamdan v. Rumsfeld) and Israel’s Supreme Court. See A. Bianchi/Y. Naqvi, International Humanitarian Law and Terrorism, Oxford 2011, p. 28.

  6. 6.

    This is the case with regard to the attacks against aircraft at Lockerbie and Flight UTA 772 attributed to Libyan-sponsored terrorists, A. Bianchi/Y. Naqvi, supra note 5, p. 14.

  7. 7.

    See M. Wood, The Role of the UN Security Council in Relation to the Use of Force against Terrorists, in: L. van den Herik/N. Schrijver (eds.), supra note 4, pp. 317–333 (319).

  8. 8.

    See the mandate of the Security Council Counter-Terrorism Committee as described on its homepage at

  9. 9.


  10. 10.

    See with regard to this subject N. Lavranos, UN Sanctions and Judicial Review, in: J. Wouters/P. A. Nollkaemper/E. de Wet (eds.), The Europeanisation of International Law, The Hague 2008, pp. 185–204; N. Lavranos, The Impact of the Kadi Judgment on the International Obligations of the EC Member States and the EC, in: P. Eeckhout/T. Tridimas (eds.), Yearbook of European Law 2009, Oxford 2010; P. Hilpold, EU Law and UN Law in Conflict: The Kadi Case, in: A. von Bogdandy/R. Wolfrum (eds.), Max Planck Yearbook of United Nations Law, Vol. 13, Leiden/Boston 2009, pp. 141–182; P. Hilpold, UN Sanctions Before the ECJ: the Kadi Case, in: A. Reinisch (ed.), Challenging Acts of International Organizations Before National Courts, Oxford 2010, pp. 18–53 and G. de Búrca, The European Court of Justice and the International Legal Order After Kadi, in: Harvard International Law Journal 51 (2010), pp. 1–50.

  11. 11.

    See M. Wood, supra note 7, p. 322.

  12. 12.

    By SC Resolution 1816 (2008) of 2 June 2008, States co-operating with the Transitional Federal Government of Somalia were authorized to enter the territorial sea of Somalia for the purpose of repressing acts of piracy and armed robbery at sea and to use, in a manner consistent with action permitted on the high seas with respect to piracy under relevant international law, all necessary means to repress such acts.

  13. 13.

    International Court of Justice, Case concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), ICJ Reports 1986, Judgment of 27 June 1986.

  14. 14.

    UN Doc. A/Res/3314 (XXIX).

  15. 15.

    International Court of Justice, supra note 13, Dissenting Opinion by Judge Sir Robert Jennings, p. 533.

  16. 16.

    International Court of Justice, Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion, ICJ Reports 2004, para. 139. Also see Judge Higgins, Separate Opinion as well as Judge Buergenthal, Declaration.

  17. 17.

    Id., paras. 146–147.

  18. 18.

    Report of the Secretary-General’s Panel of Inquiry on the 31 May 2010 Flotilla Incident, July 2011, Annex I, para. 41, 93, cited according to St. R. Ratner, Self-defence against Terrorists: the Meaning of Armed Attack, in: L. van den Herik/N. Schrijver (eds.), supra note 4, pp. 334–355, at p. 337.

  19. 19.

    See D. Bethlehem, Principles Relevant to the Scope of a State’s Right of Self-defense against an Imminent or Actual Armed Attack by Non-State Actors, in: American Journal of International Law 106 (2012), pp. 770–777.

  20. 20.

    L. van den Herik/N. Schrijver, Leiden Policy Recommendations on Counter-terrorism and International Law, 2010, para. 38; E. Wilmshurst, The Chatham House Principles of International Law on the Use of Force in Self-Defence, International & Comparative Law Quarterly 55 (2006), principle 6.

  21. 21.

    E. Wilmshurst, supra note 20, p. 12.

  22. 22.

    Id., p. 13.

  23. 23.

    Id., para. 42; D. Bethlehem, supra note 19, principle no. 12.

  24. 24.

    Several authors supported the accumulative theory, even though usually strict conditions were attached. See for example A. Cassese, The International Community’s “Legal” Response to Terrorism, in: International & Comparative Law Quarterly 38 (1989), pp. 589–608, at p. 596.

  25. 25.

    Anticipatory measures require that “the threat should be real, verifiable and leaving no choice of other means to deflect it. Only then may the use of force in anticipatory self-defence within the strict limits of proportionality be justified.” See N. A. Shah, Self-defence, Anticipatory Self-defence and Pre-emption: International Law’s Response to Terrorism, in: Journal of Conflict and Security Law 12 (2007), pp. 95–126, at p. 103.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Peter Hilpold .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2016 Springer International Publishing Switzerland

About this chapter

Cite this chapter

Hilpold, P. (2016). The Applicability of Article 51 UN Charter to Asymmetric Wars. In: Heintze, HJ., Thielbörger, P. (eds) From Cold War to Cyber War. Springer, Cham.

Download citation

Publish with us

Policies and ethics