Technology is advancing faster than ever before. Unfortunately, this technological progress has also led to the drastic changes in the nature of warfare, such as lethal automated weapons systems, outer-space conflicts, and cyber-attacks. In 2011, the 34th ICRC Roundtable on current issues involved significant discussions on the prohibition of new weapons technologies. The conference reports reveal considerable support for the belief that these weapons violate the principle of discrimination, but they make no mention of another possible source of proscribing new weapons technologies which has generated considerable recent debate – The Martens clause. This is especially surprising because the clause was frequently invoked during the efforts to draft the recent Treaty Prohibiting Nuclear Weapons, bringing up a century-old controversy on its use and application, which we have sought to explore in this post.
The Martens clause is an eponymous paragraph, first added to the preamble of the Hague Conventions, which has achieved the status of international custom. It states, inter alia, that in situations not explicitly covered by treaties; established customary international law, principles of humanity and the dictates of public conscience will apply. The principles of humanity include (i) a legal limit on acceptable means and methods of warfare; (ii) a distinction between persons participating in military operations and the civilian population, which must be protected; and (iii) a prohibition against attacking civilians.
The UN and the ICRC have been particularly influential in the development of new treaty law to ban new weapons which violate the fundamental rules of IHL, including the principle of distinction. The United Nations and the ICRC each have several ways of advocating these issues including General Assembly resolutions, the deployment of peacekeeping forces and facilitating the drafting of treaties prohibiting new weapons. Consequently, the Martens clause could be used to provide legal heft to further other similar advocacy efforts, which have proven to be critical in creating global consensus, especially in the creation of the Ottawa Treaty.
Unpacking the Divergent Interpretations
The extent of the legal weight attached to the clause remains disputed amongst scholars because of the unclear contours of the language used. One interpretation of the clause introduces obligatory sources of natural law, which fill the gaps in traditional law.
On the other hand, Antonio Cassese, who was President of the ICTY and the Special Tribunal for Lebanon and an authoritative scholar on ICL and Human Rights law, does not recognise the clause as an independent rule in itself. He contends that the clause serves a dual purpose: in the first instance, it acts as an interpretative guide for the construction of other international rules ie. IHL rules must confirm to the clause. Secondly, it elevates opinio juris to an independent source of international custom in the context of International Humanitarian law, even in the absence of any State practice. Both these approaches lead to the conclusion that the clause acts as an imperative rule, which in turn creates an obligation to proscribe all acts and means of warfare which transgress international custom, principles of humanity and the dictates of public conscience. In such a scenario, an analogy may be drawn between the concept of the rule of recognition propounded by HLA Hart, in the context of a domestic legal structure, and the application of the Martens clause to situations of armed conflict.
Arguments in Favour of Use
The clause may be used for furthering the application of human rights norms as a part of humanitarian law, as was argued by Australia in the ICJ Advisory opinion on Nuclear Weapons. The Finnish delegate at the Diplomatic Conference for the Establishment of the Additional Protocols to the Geneva Conventions adopted the same view. The clause could therefore justify the extra-territorial application of human rights involving non-state actors.
In the most clear and consistent manifestation of this interpretation, the ICRC successfully invoked the clause to champion the Ottawa treaty, the Protocol on Blinding Laser Weapons, and the Treaty on the Prohibition of Nuclear Weapons.
A strong indication of support for Cassese’s view is that the ICTY categorised the prohibition against torture as a principle of humanity while relying on the Martens clause. It was prosecuted as an international crime even when there was no explicit mention of it in the statute, and when there was a lack of state practice to establish it as International Custom. Similarly, the ICC could expansively interpret the Rome Statute to prosecute crimes proscribed by IHL.
The recommendation of the International Union for Conservation of Nature endorses the use of the Martens clause for environmental protection in armed conflicts. Therefore, deploying peacekeepers in Darfur based upon the imperative dictates of public conscience would overcome fault-lines in environmental treaties and international custom and proscribe disproportionate harm to the environment as a consequence of armed conflict.
Arguments Against Use
Considerable support exists for the view that the Martens clause does not create any legal obligations beyond that of a simple guideline. The clause is not universally recognised as creating new sources of international law, even by the ILC. Schwarzenberger forcefully argued that recognising entirely new sources of international custom opposite to traditional sources amounts to an abuse of the clause. Even the argument made by Cassese, that elevated opinio juris trumps a lack of state practice, was rejected by the ICRC Steering Committee of Experts.
Dictates of Public conscience may not always encourage the protection of civilians – for example, a declaration that ‘no quarter will be given’ would enjoy populist support in the heat of full-scale war but it would egregiously contravene the fundamental tenets of IHL.
States often disagree about new weapons and few instruments proscribing their use have been formed or received significant support. The legality of actions not expressly prohibited by international instruments has been affirmed by PCIJ (SS “Lotus case” France v. Turkey,  PCIJ, Series A No. 10, ). Smaller states will fear that larger states would misuse the vague criteria of the clause to use force in cases where it would normally be impermissible. A good example is the invasion of Afghanistan by the U.S.A. on the pretext of the ‘war on terror’ which was justified on the shaky basis that it furthered humanitarian principles and upheld the American responsibility to prevent breaches of IHL.
Originally designed as a political compromise, expanding the scope of the clause would go well beyond legislative intention. Extensive codification of IHL since its creation provides a clear structure of uniformly applicable positive rules. It has been argued that this means that the clause now serves no purpose beyond stating the obvious, rendering it redundant (Report of the Secretary-General, Respect for Human Rights in Armed Conflicts, A/8052).
The above-mentioned argument for reading IHRL into IHL has been rejected before. The ICJ has held in the Corfu Channel case that IHL and human rights law cannot be conflated and reading human rights norms into IHL would overstep the limits of Common Article 3 of the Geneva Conventions of 1949. The court also rightly pointed out that eradicating the threat of inhumane weapons and acts might paradoxically inhibit armed conflict, which makes their elimination undesirable.
There is no doubt that the Martens clause has received continuous and widespread support, evidenced by its continued use in modern IHL instruments. However, we find it highly unlikely that the inclusion of the clause in contemporary treaties can be interpreted to mean that it creates new sources of IHL. Even Cassese himself concluded that using the clause for interpreting new crimes into IHL would be incorrect. Conversely, claims that it is nothing more than a redundant relic seem well off the mark. In our view, the clause should be viewed as stating neither philosophy, nor legally binding rule. It is a statement of crucial principles, which have a strong persuasive force in the manner in which states act and form treaties for prohibiting hitherto unanticipated acts and weapons, without being obligatory rules. It is the guiding force for all IHL codification and action, but it cannot, by itself become the source of a prohibition. Consequently, soft advocacy for the evolution of IHL can, and should rely upon the principles of the clause, but it would not be possible to bind states towards a particular path based upon the clause. This would overstep the clause as it was formed by F. Martens and how it is applied today.