By Mitch Poulin, Program Associate for Global Affairs and International Affairs
On March 5 and 6, 2025, the Academy’s Global Security and International Affairs program area convened an exploratory meeting at the House of the Academy to examine the effectiveness, limitations, and trajectory of international humanitarian law (IHL) in the context of the changing character of armed conflict and a weakening commitment to the rule of law. Titled “The Future of the Laws of Armed Conflict,” the meeting was led by the cochairs of the Academy’s Committee on International Security Studies, Jennifer Welsh (McGill University) and Scott Sagan (Stanford University), and included international legal experts, policymakers, and global security scholars.
Participants generally agreed that IHL is facing a crisis due to several significant challenges, including widespread and flagrant violations of key legal principles; intensifying geopolitical tensions and the risk of great power war; new technological developments such as autonomous weapons systems and the application of artificial intelligence in military operations; and the global erosion of democratic norms. The discussion highlighted five key areas of concern among participants: 1) whether IHL remains relevant in shaping the behavior of belligerents in today’s armed conflicts; 2) the evolution in nuclear weapons doctrines in key states and whether such doctrines can be compatible with the laws of armed conflict; 3) the effectiveness (or ineffectiveness) of international courts in ensuring compliance; 4) the limitations of IHL in addressing the full range of civilian harms; and 5) the intended audience of IHL—who it applies to and whose behavior and attitudes it influences.
Although there was some consensus that IHL is still relevant in shaping the behavior of states and non-state actors, participants disagreed both on how effective it remains and on the efficacy of various approaches to strengthening compliance. Some believed that states’ strong assertions of compliance demonstrated IHL’s enduring influence, even when legal experts view states’ actions as clear violations. Others pointed out that some actors frequently reinterpret IHL principles, such as proportionality, in ways that justify excessive civilian harm and advance belligerents’ pursuit of victory.
Participants also explored the various mechanisms for enforcing IHL compliance. The International Criminal Court (ICC) was discussed at length, recognizing its role in identifying and adjudicating wartime actions that constitute international crimes, though its power to enforce its judgments is limited. While some viewed courts as essential for upholding legal frameworks, others noted that sanctions and diplomatic pressure might be more effective in encouraging compliance. The discussion also focused on the extent to which state militaries, non-state armed actors, and policymakers use IHL in their decision-making processes.
Another area of focus was the limitations in the scope of IHL. While this body of law provides a legal framework for regulating combatant activity and protecting civilians from certain kinds of harm, there are also key gaps that have been addressed—to varying degrees—through other legal and political mechanisms, such as restrictions on arms transfers, prohibitions on the use of particular weapons, and the application of human rights laws in armed conflict situations. The participants also discussed nuclear proliferation and potential scenarios for the use of nuclear weapons. Many agreed that nuclear use in wartime is fundamentally incompatible with IHL, given its inherent challenge to principles such as proportionality and the distinction between combatants and non-combatants. At the same time, there was recognition that the nuclear doctrines of key states are in flux, raising more general questions about how international law struggles to regulate modern warfare effectively.
Participants also discussed the audiences for whom IHL is most relevant. While IHL has been studied primarily by legal scholars and political scientists, and is referenced by state militaries, lawyers, and humanitarian actors, participants noted the growing interest among the general public in understanding and condemning IHL violations during ongoing conflicts. The discussion emphasized the need to raise awareness of both IHL’s strengths and limitations. Participants also noted that politicians are often influenced by public attitudes and pressure, and though most constituents may not always interpret IHL correctly, research suggests that their moral instincts generally align with IHL’s fundamental principles. Some expressed hope that increasing public awareness of and engagement with IHL could influence the decision-making of conflict parties, and ultimately improve IHL compliance.
In the context of the broader erosion of an international rule of law, IHL faces an uncertain future. The meeting highlighted IHL’s ongoing relevance, but also stressed the urgent need for a recommitment to its principles, the development of more creative and effective strategies to bring about compliance, and efforts to address the broader trend in declining respect for law. Participants noted that though IHL has faced crisis before, maintaining a legal framework to regulate today’s armed conflicts and protect civilians is a particularly daunting challenge, necessitating renewed efforts from researchers, governments, international organizations, and civil society.
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