This article explores the possibility of elaborating a strong rights foundation for ‘weak’ legal pluralist arrangements, consisting of the recognition by the state of a degree of autonomy for the legal practices of minorities. It finds unhelpful and reductionist those arguments based merely on whether certain aspects of minority law are in violation of human rights or are more effective at protecting rights than state law. Instead, the article seeks to tackle the central issue of whether there is more generally a human rights case for legal pluralism, despite the modern rights movement's strong historical association with state monism and egalitarian universalism. Traditional rights bases for minority protection, both group and individual based, are envisaged specifically from the point of view of recognition of minority legal traditions. Both are found to raise difficulties that are magnified by the entry into play of legal considerations. When it comes to collective rights, there is a fear that endowing certain communities with legal autonomy will increase their ability to oppress the minority within; when it comes to individual rights, the idea of a ‘right to one's law’ misses the degree to which law is an institutional construct which requires a new division of power within the state that goes far beyond what are generally understood as basic freedoms. Rather than assessing the problem merely from an individual or group point of view, the rights validity of legal pluralist arrangements is seen as dependent on how they relate to society at large. Specifically, a case is made that legal pluralism can be part of a beneficial coming to terms by societies with their diversity, a reinforcement of democratic forms and, in some cases, a type of transitional justice that recognises the extent to which the deprivation of law has been a traditional means of subjugation of minorities. The article concludes with an effort to recast the entire debate from the point of view of international human rights law and to critique its somewhat arbitrary focus on the state as the only locus of significant legal diversity.

Section IX of the ICRC Interpretive Guidance on Direct Participation in Hostilities asserts: ‘In addition to the restraints imposed by international humanitarian law on specific means and methods of warfare, and without prejudice to further restrictions that may arise under other applicable branches of international law, the kind and degree of force which is permissible against persons not entitled to protection against direct attack must not exceed what is actually necessary to accomplish a legitimate military purpose in the prevailing circumstances’. The present article scrutinises arguments that have been, or can be, advanced in favour of and against a ‘least harmful means’ requirement for the use of force in situations of armed conflict as suggested in Section IX. The principal aim of the article is to examine the question whether such an additional proportionality requirement forms part of the applicable international lex lata.

A military operation is about to take place during an ongoing international armed conflict; it can be carried out either by aerial attack, which is expected to cause the deaths of enemy civilians, or by using ground troops, which is expected to cause the deaths of fewer enemy civilians but is expected to result in more deaths of compatriot soldiers. Does the principle of proportionality in international humanitarian law impose a duty on an attacker to expose its soldiers to life-threatening risks in order to minimise or avert risks of incidental damage to enemy civilians? If such a duty exists, is it absolute or qualified? And if it is a qualified duty, what considerations may be taken into account in determining its character and scope?

This article presents an analytic framework under the current international humanitarian law (IHL) legal structure, following a proportionality analysis. The proposed framework identifies five main positions for addressing the above queries. The five positions are arranged along two ‘axes’: a value ‘axis’, which identifies the value assigned to the lives of compatriot soldiers in relation to lives of enemy civilians; and a justification ‘axis’, which outlines the justificatory bases for assigning certain values to lives of compatriot soldiers and enemy civilians: intrinsic, instrumental or a combination thereof. The article critically assesses these positions, and favours a position which attributes a value to compatriot soldiers' lives, premised on a justificatory basis which marries intrinsic considerations with circumscribed instrumental considerations, avoiding the indeterminacy and normative questionability entailed by more expansive instrumental considerations.

‘Force protection’ is a primary concern of every military commander. Undoubtedly, it is an important and legitimate factor in the planning of every attack. However, when it comes to the humanitarian proportionality principle there is considerable controversy over the question to what extent ‘force protection’ can be factored into the humanitarian proportionality calculus as a relevant military advantage to be weighed against expected civilian casualties, injuries and damage. This question is pursued in this article.

Recent years have seen increasing reliance on self-defence as a concept justifying the use of force against armed attacks by terrorists operating from within a foreign state. While the matter has prompted major debates, a good case can be made that contemporary international law now begins to recognise a right of self-defence against attacks by terrorists. (We will refer to this in the following as ‘anti-terrorist self-defence’, meaning a response directed against an attack carried out by a terrorist organisation.) This article deliberately does not rehearse the major debates about the scope of self-defence, but moves beyond them. It seeks to assess whether and how the two main limitations on the exercise of self-defence – namely necessity and proportionality – could be adapted to self-defence outside the inter-state setting. It shows that both limitations do indeed require some adaptation in order to be applied to anti-terrorist self-defence.

With respect to necessity, we argue that this adaptation is actually a chance to make sense of a requirement that is of very limited practical relevance in the inter-state setting. As the article shows, necessity can assume a crucial role in the anti-terrorist setting: in order for trans-border uses of force to be necessary, states invoking self-defence must demonstrate that the terrorist threat cannot be repelled by the host state (on whose territory the terrorists are based).

As for proportionality, recent debates about anti-terrorist self-defence expose the weaknesses of proportionality as a restraint on self-defence. Construed primarily as a prohibition against excessive force, even in the inter-state setting, proportionality has always been dependent on the nature of the aims pursued in the name of self-defence. Recent anti-terrorist practice suggests that many states are prepared to accept far-reaching uses of force against terrorists. It also suggests that, in applying proportionality, the targeted (or otherwise) character of the response is of crucial importance. The law is clearly in a state of flux, but in debates such as those about Turkey's use of force against the PKK or Israel's military operations against Hamas or Hezbollah, one can see the beginning of a process of developing guidelines on proportionality.

Proportionality is a condition provided under both jus ad bellum and jus in bello. Based on a particular interpretation of state practice and international case law, recent legal literature argues that the two notions of proportionality are interrelated in that proportionality under jus in bello is included in the assessment of proportionality under jus ad bellum. This article seeks to refute such a position and, more generally, to clarify the relationship between the two notions of proportionality.

The main argument of the article is in line with the traditional position regarding the relationship between jus ad bellum and jus in bello. It is argued that, although sharing common features and being somewhat interconnected, the notions of proportionality provided under these two separate branches of international law remain independent of each other, mainly because of what is referred to in this article as the ‘general versus particular’ dichotomy, which characterises their relations. Proportionality under jus ad bellum is to be measured against the military operation as a whole, whereas proportionality under jus in bello is to be assessed against individual military attacks launched in the framework of this operation.

This article nonetheless emphasises the risk of overlap between the assessments of the two notions of proportionality when the use of force involves only one or a few military operations. Indeed, in such situations, the ‘general versus particular’ dichotomy, which normally enables one to make a distinct assessment between the two notions of proportionality, is no longer applicable since it becomes impossible to distinguish between the military operation as a whole and the individual military attacks undertaken during this operation.

The principle of proportionality, notoriously obscure in application and subjective in interpretation, has been enforced so rarely as to call into question its potency as a meaningful international legal standard. Nonetheless, international criminal tribunals, academics, and the ICRC's monumental study on customary international humanitarian law all confidently proclaim the principle as embedded in the customary international law applicable to both international and non-international armed conflicts. To assess whether these claims are accurate, and to flesh out how states interpret the principle in practice, the author and a colleague have undertaken a long-term, multinational empirical study of state practice in interpreting and enforcing the proportionality principle. This article discusses the methodological options available and explains the one chosen for the proportionality study. The limitations of the study, in spite of its deliberate methodology, suggest that the debilities of the proportionality principle may not be conceptual as much as a byproduct of unnecessary military secrecy. This article concludes that greater transparency in state compliance with the rule of discrimination and the principle of proportionality would, at least, facilitate an understanding of how the hitherto obscure principle operates in practice and, at best, could create systemic effects that would decrease the dangers to civilians in armed conflicts.

There is a tendency among the judiciary to apply the standard of ‘effective control’ as the applicable yardstick for apportioning responsibility for wrongful acts between the United Nations and the member states contributing troops to UN peace-support operations. This is evidenced by recent decisions in the cases of Srebrenica (Dutch Court of Appeal, 2011), Al Jedda (European Court of Human Rights, 2011) and Mukeshimana (Belgian First Instance Court, 2010), which appear to repudiate the ‘ultimate authority and control’ standard espoused by the European Court of Human Rights in Behrami (2007). This process may have been set in motion by (the current) Article 7 of the ILC's Draft Articles on the Responsibility of International Organizations, which may in due course reflect customary international law. From a policy perspective, the application of an ‘effective control’ standard is highly desirable, as it locates responsibility with the actor who is in a position to prevent the violation.