Does Might Make Right? Reclaiming the Spirit of Kellogg–Briand in an Age of Forever Wars

August 03, 2025 - Written by Talha Haroon

When the war between Russia and Ukraine began – and, more recently, the confrontation between Israel and Palestine – many anticipated these would remain limited conflagrations. It was assumed that they could be contained within the frameworks of strategic deterrence and mutual diplomacy. Instead, they have expanded into protracted, open-ended conflicts, highlighting a deeper transformation in global politics – the rise of the forever war. These are defined as conflicts in which adversaries become structurally locked into hostility, driven by domestic imperatives or entrenched systemic constraints. As scholars of international law and conflict have noted, contemporary warfare is increasingly governed by open-ended legal rationalisations that enable its indefinite extension. This routinisation of war stands in stark contrast to a collective political intervention undertaken nearly a century ago – the Kellogg-Briand Pact of 1928 (hereafter, the Pact). 

Sixty-three nations (including the United States, France, Germany, and Japan) signed the Pact, formally renouncing war as an instrument of national policy. Emerging from the devastation of the First World War, the Pact sought to dismantle the view that war was a sovereign right for nations to pursue territorial, political, or economic ends. Conversely, the Pact reframed war as a legal wrong and collective crime. As Bunck and Fowler argue, it marked “an important early venture in multilateralism” and “played a role in the development of a new norm of behaviour in international relations” helping to criminalize war and redefining its use as a tool of statecraft. While the Pact became burdened by the absence of enforcement mechanisms (an issue that continues to challenge modern supranational institutions such as the United Nations), its normative ambition remains singular in its significance. Consequently, this article contends that recovering the key principles of the Kellogg–Briand Pact in an age of forever wars is necessary to apprehend the roots of conflict today. 

The Juridical Principles of War

For much of modern history, the right to wage war was embedded in the sovereign prerogative of states. Rooted in the jus ad bellum tradition – codified most notably by Hugo Grotius in De Jure Belli ac Pacis (1625) – international law upheld war as a legitimate instrument of statecraft when pursued under ostensibly just causes. In this paradigm, legality hinged not on the act of violence itself but on the justification for it. As Martti Koskenniemi argues, international law assumed a dual function: legal arguments did “not produce substantive outcomes” alone but sought to “justify them.” Consequently, the distinction between war and peace became a matter of politicised narratives where military action could be cloaked as “self-defence” or condemned as “aggression,” depending on the political frame. This flexibility has underwritten our age of forever wars, where international law has become inept at constraining violence. For instance, the U.S. intervention in Afghanistan, initially authorised as self-defence in 2001, gradually morphed into a decades-long project of counter-insurgency and state-building, yet remained anchored in the original justification. As Richard Maass notes, “international law’s current approach to aggression as a subset of war allows the grey zone to function as an area ripe for norm evasion”. Article 2(4) of the UN Charter – once the cornerstone of anti-war jurisprudence – is now repeatedly bent to allow for differing interpretations, allowing states to wage sustained military campaigns without ever formally engaging in war.

It was precisely this pattern of political and legal evasion that the Kellogg–Briand Pact of 1928 sought to disrupt. Rather than specifying the conditions under which war might be justified, the Pact rejected war itself as a lawful instrument of international conduct. As Oona Hathaway and Scott Shapiro argue, the “outlawry of war set in motion a transformation in the international legal order” by reclassifying war from a sovereign entitlement into a juridical wrong. This shift was most visibly institutionalised at the Nuremberg Trials, where the prosecution of crimes against peace marked the first instance of unchecked hubris being treated as a punishable international crime. Without this normative redefinition, Meltzer notes, acts of violence were “not punishable if they were an incident of any war, whether or not aggressive…all wars were considered legitimate national activity, which conferred a privilege to kill and destroy”.

However, the legal foundations laid at Nuremberg have been considerably weakened in the post-9/11 international order. Conflicts in the Middle East and parts of Africa (many sustained under self-defence mandates) demonstrate the difficulty of applying legal constraints to contemporary warfare. The threshold for identifying aggression has become increasingly ambiguous, allowing states to justify prolonged military engagement without formal declarations of war. In this context, the Kellogg–Briand Pact remains relevant, not because of enforcement, but because it altered the way we think about the legal presumptions of war. 

Legal Grey Zones Underpinning Modern Warfare

The post-1945 legal order sought to establish clear restraints on the use of force. Yet in the modern era, these restraints have come under increasing strain. The global response to Russia’s full-scale invasion of Ukraine in 2022 briefly reaffirmed the normative force of the anti-war framework. Despite Moscow’s invocation of self-defence, the legal basis for its aggression was widely rejected. In March 2022, the International Court of Justice issued a provisional ruling dismissing Russia’s claims of genocide in Donbas and called for the immediate suspension of military operations. Similarly, the UN General Assembly passed multiple resolutions condemning the invasion and reaffirming the centrality of the prohibition on the use of force. While these actions signalled a degree of legal consensus, they also underscored a growing gap between the articulation of norms around inciting war and the capacity of enforcement.

This tension was further highlighted in 2023 when the International Criminal Court (ICC) issued an arrest warrant for President Vladimir Putin and his Commissioner for Children’s Rights, Maria Belova, citing their personal responsibility in the unlawful deportation of Ukrainian children to Russian-held territories. Although largely symbolic (given Russia’s non-membership in the Rome Statute and its rejection of ICC jurisdiction) the warrant marked a watershed moment: the first time a sitting head of state from a permanent UN Security Council member facing prosecution under international law. Importantly, the basis of the indictment lay in the specific conduct of war, reflecting the evolution of legal accountability first set in motion by the Kellogg–Briand Pact. Yet even as this framework matures in legal form, its enforcement remains constrained by geopolitical dynamics. Russia’s veto power within the UN Security Council effectively neutralises any Chapter VII enforcement – the clause which authorises the UNSC to take enforcement measures to maintain or restore international peace and security. This highlights what Antonio Cassese has noted as the inability of the international legal system to “penetrate national legal systems and make its commands operative.” Thus, the war between Russia and Ukraine reveals the systematic circumvention of standards set around war by powerful states, not least due to the absence of parameters brought about through the Pact.  

This circumvention is also present in the Middle East, where legal thresholds for the use of force have eroded into near irrelevance. Israel’s military campaign in Gaza has led to widespread destruction of civilian infrastructure and mass displacement. While Israel cites self-defence under Article 51 of the UN Charter, the scale and persistence of the operations have prompted leading jurists to question whether the principle of proportionality has been disregarded. Meanwhile, the exchanges between Israel and Iran – involving proxy actors and cross-border strikes – are steeped in legal grey zones. The attacks on nuclear sites in Iran were framed as “pre-emptive” or “preventive” responses rather than formal declarations of war, but this enables actors to sidestep the legal responsibilities that come with declared hostilities. As with Russia, legal justifications in the Middle East remain post-hoc, revealing a global pattern where the use of force is increasingly legitimised through strategic reinterpretation rather than objective legal criteria.

Returning to the Pact, Rebuilding Order

Contemporary conflicts showcase that the pattern of selective application of international law is a symptom of the broader degradation of global order. Where wars were once bracketed by formal declarations and constrained by identifiable endpoints, they now unfold with impunity. In this context, returning to Kellogg-Briand offers a blueprint to restore the robust mechanisms that prevented war for decades. To some, reviving the pact may seem politically idealistic. Yet, despite its limitations, it embodies a critical legal and moral principle: war – whether waged for strategic, economic, or ideological ends – must not go unchecked. 

Reaffirming this principle requires rebuilding trust in international institutions, ensuring the consistent application of norms, and resisting the rhetorical drift that renders the use of force permissible. This does not entail that new prohibitions be created; rather, returning to the Pact restores the authority of existing checks/balances and reasserts that war be justified only under the most extraordinary of circumstances. Ultimately, as history has shown, the weakening of anti-war norms does not merely expose the world to conflict; it risks entrenching war as a permanent condition of life. The cost of that shift – visible in today’s forever wars – is not only legal or political, but fundamentally human.

Written by Talha Haroon

Analyst and Editor