The “othering” of international humanitarian law has a demonstrated past resulting from the exclusion of so-called “Enemies of the Faith” from the laws of chivalry. It is no surprise, then, that the idea of “sharp war” should seem so natural to some commentators given its historical application “by the discretion of the commander and such rules of justice and humanity as recommend themselves in the particular circumstances of the case”. The application of humanitarian principles, in other words, was the measure of the commander's charity rather than the result of legal compulsion.

The viability of sharp war appears to have increased in attractiveness as conventional State-on-State warfare has seemingly decreased in frequency; however, the question of sharp war has never been approached through a legal historical lens. Utilizing the research found in The Laws of Yesterday's Wars, a multi-author series edited by the present author, this paper seeks to fill this gap by scoping over a range of geographically and temporally disconnected case studies and the customary law developed to mitigate warfare. Ultimately, the paper highlights that “soft war” has naturally evolved in all cultures and that arguments for sharp war are a historical anomaly.

This article provides the personal perspectives of US military operational attorneys and analyzes three significant challenges in applying international humanitarian law (IHL) to modern military space operations: the lack of clear standards for assessing when IHL rules govern particular military activities in outer space; the challenges of effectively distinguishing between civilian objects and military objectives when targeting space systems; and the difficulties of applying IHL rules of proportionality when attacking space systems. To address these challenges, the article argues that States should take steps to develop non-binding norms for military space operations that contribute to broader understanding of States’ views on how IHL applies in space.

This year marks the 160th anniversary of the original Geneva Convention and the 75th anniversary of the four Geneva Conventions of 1949. Together, they have come to embody our common humanity. Alas, recent history teaches us that nothing can be taken for granted – whether people's basic rights or peace.

How international law applies to the use of information and communications technology by States is still a matter of discussion. Against this background, cyberspace has become the main area of competition between States, and this competition, to put it simply, is resulting in a constant low-intensity warfare below the threshold for a use of force. Such low-intensity cyber warfare, from a legal point of view, revitalizes the debate over the concept of a “state of intermediacy” that has the potential to overcome the dichotomy between peace and war. In the present author's opinion, this state of intermediacy also supports the idea that the international humanitarian law (IHL) principle of distinction should be applied, even before the eruption of a full-scale war, whenever wartime means and capabilities are employed by States. This paper argues that some opacities in international law have created favourable conditions for such constant low-intensity warfare, and that tackling the identified opacities would therefore be beneficial in order to achieve a more peaceful cyberspace. Thus, the paper goes on to address one of the identified opacities, namely the definition of espionage under international law, because, as international law now stands, it does not allow us to tackle the other identified opacities. Finally, the paper discusses how the proposed narrow interpretation of espionage can cope with the IHL principle of distinction in the cyber domain.

Neutrality, a foundational principle in humanitarian efforts and peace mediation, encounters significant practical challenges in the modern landscape of armed conflicts, particularly in the intermediary role of humanitarian organizations. This study examines the role of the International Committee of the Red Cross (ICRC) as a neutral intermediary in Yemen, focusing on the release and repatriation of detainees during the 2016–20 peace efforts. Drawing on the ICRC's experience, the analysis highlights the evolving understanding of neutrality from a rigid concept to a more flexible, context-sensitive approach. The findings emphasize the importance of neutrality in fostering trust and facilitating dialogue while acknowledging the operational complexities and strategic considerations involved. This study provides insights into enhancing the contributions of neutral intermediaries to sustainable peace processes.

Newly emerging US cyberspace warfighting concepts highlight the need to update US legal doctrine. Concepts adapted to future high-intensity, high-paced armed conflict, including command post dispersal and integration of cyberspace into other targeting domains, present opportunities to refine US understandings of the law of war attack threshold and overlooked rules applicable to destruction and seizure. The advantages of staking out clear and current opinio juris on these and other matters extend beyond providing responsible and consistent operational law advice. Updated and authoritative military cyber legal doctrine will serve the strategic and diplomatic legal interests of the United States and the international legal system as a whole.

Bearing in mind that the peace process between the Colombian government and the Revolutionary Armed Forces of Colombia – People's Army (Fuerzas Armadas Revolucionarias de Colombia – Ejército del Pueblo, FARC-EP) has been an important milestone for transitional justice, this article aims to share some of the good practices and achievements of this process, as well as the setbacks and challenges that could be avoided in future peace processes. The article will highlight relevant contributions from the Chamber for Amnesty or Pardon (CAP) such as impacting the resocialization of former FARC-EP members and developing international humanitarian law discussions in relation to war crimes and less serious crimes. Additionally, it will describe some of the main challenges faced by the CAP, such as the high number of applications for transitional benefits that it receives, the high number of proceedings that it supervises, and the security concerns arising from implementing a peace agreement in a country still in conflict.

Franz Perrez is Director-General of the Directorate of International Law at the Federal Department of Foreign Affairs (FDFA), Switzerland. He is responsible for the development and interpretation of international law and ensuring that Switzerland's strategic rights are respected abroad. As a member of the FDFA senior management, Mr Perrez is also jointly responsible for the FDFA's strategic approach and advises the Federal Council, Switzerland's representatives abroad and other Federal Administration offices on international law issues.

Prior to his new role Mr Perrez was appointed Switzerland's Ambassador for the Environment and Head of the International Affairs Division at the Federal Office for the Environment (FOEN) in 2010. In this capacity, he headed the Swiss delegations to international environmental and climate negotiations for thirteen years.

After studying law in Bern and Paris, Mr Perrez worked at the FDFA's Directorate of International Law from 1993 to 1995. He went on to study at New York University, where he gained a master of laws focusing on international law and completed a PhD thesis on the topic of sovereignty as a principle of cooperation. On returning to Switzerland, he took up a position at the World Trade Organization (WTO) Division of the State Secretariat for Economic Affairs, before joining the FOEN in 2001.

Mr Perrez has proven expertise in international law. He has widely published in the area of international environmental law, international environmental governance, the relationship between trade and the environment, and public international law. Since 2008, Mr Perrez has also lectured on international environmental law at the University of Bern School of Law. He served as a panellist on the newest WTO tuna–dolphin dispute between Mexico and the United States, and as Switzerland's Ambassador for the Environment and Chief Negotiator for Environmental Issues, namely climate change, biodiversity, chemicals and waste, he led the Swiss delegation to the Rio+20 conference and to the Paris Climate Change Conference in 2015. He was President of the Basel Convention (COP 11 in 2013) and President of the Rotterdam Convention (COP 8 in 2017) and facilitated the negotiations on mitigation of the Paris Agreement. Through his work within and outside of Switzerland, he has built strong networks around the world and within the Federal Administration.

This article explores the role of Article 6(5) of Additional Protocol II to the Geneva Conventions in balancing justice and peace during transitions from armed conflict to peace. It argues that the provision, which encourages the granting of broad amnesties at the cessation of hostilities, requires a re-evaluation of the obligation to investigate, prosecute and punish under international law. By analyzing the legal context and scope of Article 6(5), as well as its application in transitional justice models such as in Colombia, the article highlights how the principle of peace can be prioritized alongside justice without undermining victims’ rights. The discussion critically addresses maximalist interpretations of justice, presenting a nuanced approach that foregrounds restorative justice and the importance of reconciliation in post-conflict societies.

This article examines the links between the concept of peace and international humanitarian law (IHL). It takes a closer look at how the originator of IHL, the International Committee of the Red Cross, justified the existence of this body of law, which was supposed to regulate war, in the face of those who wanted to see war abolished once and for all. The article also questions the attitude of the International Red Cross and Red Crescent Movement, which, while wanting a peaceful society, did not give itself the means to achieve one.

International humanitarian law (IHL) provides the normative foundation for efforts to address the issue of missing persons during and after armed conflict. Whilst IHL does not engage with how parties to an armed conflict may go about restoring peace, there has been speculation that resolving the missing issue, by bringing answers to families about the fate and whereabouts of their missing relatives, can potentially play a role in building peace. This article represents an effort to compile existing evidence in academic and practice literature that supports an understanding of how addressing the missing issue relates to peacebuilding. In so doing, the article seeks to lay out a research agenda to understand how addressing the issue of the missing can serve to advance peacebuilding, and proposes avenues for further research.

In an era marked by growing conflicts, prolonged humanitarian needs and less donor funding, collaboration between the humanitarian and peacebuilding sectors is essential for more effective responses. This paper examines the complexities of fostering such collaboration, emphasizing the importance of integrated multisectoral approaches capable of addressing both immediate necessities and long-term peace and development objectives. While recent initiatives such as the humanitarian–development–peace nexus framework and the United Nations Secretary-General's Agenda for Humanity reflect progress toward integrated approaches, substantial collaborative challenges persist. This paper identifies three key entry points for mutual learning between humanitarian and peace actors. Firstly, it discusses a “peace-responsive” approach to humanitarian activities that proactively contributes to “peace-positive” outcomes. Secondly, it emphasizes the need for the peace sector to learn from humanitarian efforts regarding accountability to affected communities. Thirdly, it underscores the need to understand the normative foundations of each sector and their implications for joint action. Drawing on these insights, the paper offers recommendations for policy-makers and practitioners to help them advance joint approaches to humanitarian assistance and peacebuilding in conflict-affected contexts.

This article proposes a hybrid legal framework combining jus ad bellum and jus in bello to govern the attribution of State responsibility for reparations at the end of a war of aggression. To this end, the article considers former international mass claims processes and proposes a complementary approach that, on the one hand, acknowledges the role of the aggressor State in waging the war, and on the other, takes a cautionary approach to prevent a disproportionate burden of compensation being imposed on the aggressor State as a form of collective punishment. The consequences of respective violations of the prohibition of the use of force and the law of war are blurred in a war of aggression, resulting in complexities around liability for aggressor States. In response, this article concludes with a nuanced proposal to calculate compensation based on (1) the aggressor party's capacity to comply with jus in bello; (2) the extent of damage caused by the war of aggression, factoring in jus ad bellum considerations if a party is found to be intentionally maximizing destruction; and (3) the incorporation of tort law principles for equitable attribution of responsibility.

With the advent of socio-technical systems that gather and process personal data, the capacity to identify and even locate people in an automated fashion has dramatically increased. This article discusses what militaries need to know about data protection and the right to digital privacy/private life when personal data is processed. The focus in this discussion is on sensitive data that makes individuals identifiable. It is here argued that the right to data protection and the right to digital privacy/private life are distinctive and separate rights and should be treated as such, despite some overlaps. Although the law of armed conflict approaches processing of sensitive data in a topical manner, it remains firm on the delimitation between what is permissible and what becomes unlawful when it comes to processing data. This article illustrates that elements of both data protection and protection of the right to privacy/private life can be traced in the law of armed conflict. In fact, both rights remain distinctive also in times of armed conflict and must be separately protected through obligations of result as well as obligations of conduct.

Itonde Kakoma is the President and CEO of Interpeace. Prior to Interpeace, he served as the Permanent Representative of the International Federation of Red Cross and Red Crescent Societies (IFRC) to the African Union and International Organizations (2021–23). Previously, Mr Kakoma served in various leadership capacities on matters of international peace mediation, including as Director for Global Strategy and member of the leadership team at CMI – Martti Ahtisaari Peace Foundation. Additionally, Mr Kakoma was Assistant Director for the Conflict Resolution Programme at the Carter Center, managing a portfolio of the Center's peace initiatives and supporting former president Carter's back-channel diplomatic efforts. He is an experienced facilitator and moderator for high-level peace processes and dialogue fora and has expertise in mediation, negotiation, process design, humanitarian diplomacy and transitional justice.

This article outlines and evaluates several unique challenges associated with legal support to special operations. It describes the essential differences between special tactics, techniques and procedures and conventional military operations. It offers a US perspective on how treaty and customary international laws apply to various special operations, including precision attacks against “high-value targets”, hostage rescue missions, and support to partner and proxy forces. It examines the benefits and drawbacks of heavy reliance on special operations during armed conflict, including an assessment of the legal challenges that arise when special operations forces become a primary feature of a military campaign. Finally, it highlights how the assumption of substantial military and political risk impacts the application of international law to special operations at the tactical level.

When do non-international armed conflicts (NIACs) end? Determining the existence of a NIAC requires a detailed, fact-intensive inquiry. Since the International Criminal Tribunal for the Former Yugoslavia's seminal decision in the Tadić case, international courts and tribunals have evaluated the existence of NIACs under the Tadić test's two-pronged inquiry into intensity and organization. Although that decision also pronounced that international humanitarian law (IHL) continues to apply until a “peaceful settlement is achieved,” neither international tribunals nor scholars have articulated a comparably widely accepted and well-developed test for determining the end of NIACs.

At the same time – and especially since 9/11 – States have increasingly relied on IHL to meet the threat posed by non-State actors, broadening the scope of conflict-related liabilities in armed conflict without conferring the privileges or immunities otherwise inherent in IHL. This one-sided approach twists the purpose of IHL and places members of organized armed groups into legal black holes without temporal limitations, as States resist the termination of “armed conflict” irrespective of the continuing intensity of violence or the level of organization of non-State actors. Ultimately, the current approach gives States broad discretion without appropriate safeguards, which undermines the proper application of human rights and humanitarian principles within conflict and prevents the establishment of a sustainable peace.

This paper argues that the most appropriate test for ascertaining the end of a NIAC is one that combines objective consideration of the diminution of organized and intense hostilities below the Tadić threshold with the likelihood that hostilities will not again rise above that threshold. It thus draws from but does not fully endorse the preferred approach of the International Committee of the Red Cross (ICRC), which focuses on the lasting termination of hostilities,1 while abjuring a general temporal limitation. Although commendable for its effort to avoid the legal uncertainty that attends the revolving conflict classification problem, the ICRC's approach unfortunately tends to encode existing uncertainty surrounding the termination of NIACs and to indistinctly prolong the application of IHL to erstwhile conflict situations. In contrast, the authors suggest that a test for the end of NIAC based on a specific period (five months following the diminution of organized and intense hostilities below the Tadić threshold), subject to an evaluation of the risk that those hostilities may resume, better balances certainty of legal application with the promotion of a return to peace. The authors will employ the facts of diverse case studies, including the FARC in Colombia, the LTTE in Sri Lanka, numerous armed groups in Mali, and the United States with Al-Qaeda, to build a legal standard that courts can use to determine IHL's continuing applicability to an erstwhile armed conflict.

This article aims to highlight the importance of determining the temporal scope of the transition from armed conflict to peace. It will also consider the emergence of a new legal paradigm, jus post bellum, applicable to the post-conflict period, and the associated need for an appropriate regulatory framework. Given the unavoidable impact of armed conflict, the post-conflict period deserves particular attention, especially with regard to the need for a legal framework to facilitate the sustainable reconstruction of communities torn apart by conflict and ensure a lasting peace. After any kind of armed conflict, a solid legal framework is essential to finalize the end of hostilities, begin a sustainable peace process, build a united society and address the rifts caused by armed violence.

Neutral States must abstain from supporting a party to a conflict with military equipment and assistance. This core aspect of the law of neutrality has not changed with the adoption of the UN Charter in 1945, or with the brutal Russian aggression against Ukraine. That said, by reviewing the changes to neutrality law over time, this article finds plausible reasons to believe that neutrality has – for better or worse – become optional for the vast majority of States, which can today opt to be non-belligerent States – i.e., States that are neither neutral nor parties to the armed conflict. All States have to cooperate to bring to an end serious violations of international law, including humanitarian law, and this duty of cooperation has abolished “sitting-still neutrality”, but it does not render neutrality law moot. This reading of “optional but not qualified” neutrality maintains the core neutrality idea of abstaining in military matters. In this article, I argue that views of “obsolete” or “qualified” neutrality are not new at all but depart from well-accepted rules of legal interpretation and raise concerns about double standards. Viewing neutrality as optional but unqualifiable offers greater conceptual clarity, is more honest than alternative views, and comes with advantages for humanitarian action.