## Introduction
International law has traditionally viewed the regulation of weapons through the lens of international humanitarian law (IHL), a body of law specifically designed for armed conflict. As Casey-Maslen (2015) suggests, this is the instinctive response of many international lawyers. However, his assertion that international human rights law (IHRL) offers an “overarching international legal framework” to determine the legality of weapons use and supply challenges this view. This essay will critically reflect on this assertion. It will argue that while IHL and IHRL provide differing safeguards, their concurrent application often results in greater overall protection for individuals. However, this interaction is not without its difficulties, and applying both legal regimes in the same scenario can create disadvantages, particularly in relation to the standards governing the use of force. This analysis will focus primarily on the contribution of IHRL, using examples concerning weapons law, torture, and sexual violence to illustrate the advantages and disadvantages of a dual-framework approach.
## The Distinct Spheres of IHL and IHRL
To understand their interaction, it is first necessary to outline the different purposes and scopes of IHL and IHRL. International humanitarian law, also known as the law of armed conflict, applies only during situations of armed conflict. Its primary aim is to mitigate the effects of hostilities by protecting persons who are not, or are no longer, directly participating in hostilities (e.g., civilians, wounded soldiers) and by regulating the means and methods of warfare available to combatants (ICRC, 2016). Core IHL principles for weapons use include distinction (distinguishing between civilians and combatants), proportionality (not causing civilian harm excessive in relation to the military advantage anticipated), and the prohibition of weapons that cause superfluous injury or unnecessary suffering.
In contrast, international human rights law applies at all times, in peace as in war. It governs the relationship between a state and individuals within its jurisdiction, establishing fundamental rights and freedoms that the state must respect and ensure. Key rights relevant to the use of weapons include the right to life, the right to be free from torture and other ill-treatment, and the right to security of person. These rights are found in treaties like the International Covenant on Civil and Political Rights (ICCPR) and the European Convention on Human Rights (ECHR). While some rights can be derogated from during a public emergency, core rights such as the prohibition of torture are absolute and can never be suspended.
## Human Rights Law and the Regulation of Weapons
The assertion by Casey-Maslen (2015) is most clearly demonstrated in situations that fall short of armed conflict, such as law enforcement operations, including the policing of protests and riots. In these contexts, IHL does not apply, leaving IHRL as the sole legal framework governing the state’s use of force. IHRL provides a stricter set of rules than IHL. The right to life, protected by Article 6 of the ICCPR and Article 2 of the ECHR, is paramount. The use of lethal force by state agents is only permissible where it is “absolutely necessary” to protect life (UN Human Rights Committee, 1982). This is a much higher threshold than the IHL principle of proportionality in an attack.
A life example of this can be seen in the use of so-called ‘less-lethal’ weapons, such as tear gas, plastic bullets, and tasers, during civil unrest. In numerous protests around the world, from the 2020 Black Lives Matter protests in the United States to demonstrations in Hong Kong, these weapons have been used in ways that have caused serious injury and death. From an IHRL perspective, the legality of their use is judged against the principles of necessity and proportionality (Amnesty International, 2021). The question is not whether there is a military advantage, but whether the use of force was strictly necessary to counter a specific threat, and whether the degree of force used was the minimum required. The European Court of Human Rights, in cases such as *McCann and Others v United Kingdom* (1995) 21 EHRR 97, has rigorously scrutinised state operations involving lethal force, demonstrating that IHRL provides a robust framework for assessing the planning and control of such operations to minimise any risk to life. This shows a clear safeguard that IHRL offers, which is absent in situations where IHL is not applicable.
## Concurrent Application: Advantages and Disadvantages
The more complex question is whether the application of both frameworks together provides greater protection or creates conflict. In many modern security situations, such as military occupations or operations against non-state armed groups, the lines between armed conflict and law enforcement are blurred, leading to the concurrent application of both IHL and IHRL.
### Advantages of a Dual Framework
A significant advantage of applying both regimes is the reinforcement of fundamental protections. The prohibition of torture and cruel, inhuman or degrading treatment or punishment is absolute under both IHL and IHRL. Common Article 3 of the Geneva Conventions prohibits “violence to life and person, in particular murder of all kinds, mutilation, cruel treatment and torture” in non-international armed conflicts. Similarly, Article 3 of the ECHR and the UN Convention against Torture provide an absolute prohibition. The application of IHRL alongside IHL can offer greater definitional clarity and a more developed body of case law on what constitutes ill-treatment, thus strengthening protections for detainees in an armed conflict.
Similarly, the prohibition of sexual violence is a norm found in both bodies of law. IHL prohibits rape and other forms of sexual violence as war crimes (Rome Statute of the International Criminal Court, Art 8). IHRL protects bodily integrity and prohibits discrimination. By applying both, a victim of sexual violence in conflict has access to multiple accountability mechanisms. The state has a responsibility under IHRL to investigate and prosecute such crimes, while individuals may also face international criminal responsibility under the laws of war. This dual coverage creates a stronger web of protection and accountability.
### Disadvantages and Legal Conflict
Despite these advantages, applying both disciplines in the same scenario can create significant disadvantages, primarily through legal uncertainty and conflicting standards. The main point of friction concerns the rules on the use of lethal force. As discussed, IHRL permits lethal force only when “absolutely necessary” to protect against an imminent threat to life. IHL, by contrast, permits combatants to be targeted simply by virtue of their status, without needing to show they pose an immediate threat.
This clash of standards creates a major dilemma in asymmetric conflicts. For instance, in a military occupation, when does a civilian lose their protection and become a legitimate target? If a person throws a rock at an armoured patrol vehicle, under a law enforcement paradigm (governed by IHRL), lethal force would almost certainly be a disproportionate response. However, under an armed conflict paradigm (governed by IHL), if that person is deemed to be “directly participating in hostilities,” they could potentially be targeted. This is not a theoretical problem; it is a daily reality in contexts such as the Israeli-Palestinian conflict, where the applicable legal framework is constantly debated (Sassòli, 2005). This legal ambiguity can be a disadvantage, as it may be exploited by parties to the conflict to justify actions that would be illegal under one of the frameworks. This problem is often framed in the language of *lex specialis*, with states arguing that IHL, as the more specific law for conflict, should override IHRL, potentially lowering protections for individuals. However, the International Court of Justice has confirmed that IHRL continues to apply in armed conflict, subject to the application of IHL as the *lex specialis* where necessary (*Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory*, 2004).
## Conclusion
In conclusion, international human rights law provides a vital legal framework for regulating weapons, particularly in law enforcement scenarios where international humanitarian law is silent. The protections offered by IHRL and IHL are different in their scope and application, but when applied together, they can provide greater overall protection for individuals. The combined absolute prohibitions on torture and sexual violence, for example, create a more robust legal shield and offer multiple avenues for justice. However, the concurrent application of both regimes is not a perfect solution. The disadvantage of applying conflicting standards, most notably regarding the use of lethal force, creates legal uncertainty that can undermine individual protection in complex security environments. Therefore, while Casey-Maslen’s assertion that IHRL provides an “overarching framework” is a valid and important corrective to an IHL-centric view, the relationship between the two disciplines is one of both reinforcement and tension, presenting distinct advantages and disadvantages when they are applied to the same scenario.
## References
Amnesty International. (2021) *My eye exploded: The global crisis of police using rubber bullets against protesters*. Amnesty International Ltd.
Casey-Maslen, S. (2015) ‘Weapons Under International Human Rights Law’, in *Weapons Under International Human Rights Law*. Cambridge University Press, pp. 1-28.
International Committee of the Red Cross (ICRC). (2016) *Commentary on the First Geneva Convention*, 2nd edn. Cambridge University Press.
*Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion* [2004] ICJ Rep 136.
*McCann and Others v United Kingdom* (1995) 21 EHRR 97.
Sassòli, M. (2005) ‘The status of persons held in occupied territory’, *Journal of International Criminal Justice*, 3(1), pp. 96-108.
UN Human Rights Committee. (1982) *General Comment No. 6: The right to life (Art. 6)*, CCPR/C/21/Rev.1.
