Can War Be Tamed? A Historical Perspective on the Evolution of War and International Law

For much of human history, war was considered a legitimate tool for resolving international conflicts. However, a turning point came on August 27, 1928, when U.S. Secretary of State Frank Kellogg signed the Paris Pact, formally outlawing war under international law. This monumental moment marked the beginning of a new era in global diplomacy.

The Shift from War as a Right to War as a Crime

Before the Kellogg-Briand Pact, nations operated under the principle of jus ad bellum, the right to wage war. This meant that states had the sovereignty to resort to armed conflict whenever they deemed it necessary. The pact, however, sought to reverse this norm by criminalizing war as a means of political resolution. It was a bold attempt to redefine international relations, with nearly 50 countries joining the agreement by 1939.

Yet, the limitations of this pact became apparent even before World War II. Japan ignored its commitment when it invaded Manchuria in 1931, and Italy followed suit by attacking Abyssinia (modern-day Ethiopia) in 1935. Without enforcement mechanisms in place, these violations went unpunished, leading many to question the pact's effectiveness.

The Post-War Reinforcement of Peace

Despite its shortcomings, the 1928 pact laid the groundwork for the establishment of the United Nations in 1945. The UN Charter further expanded on the principles of war prohibition, explicitly outlawing not only war but also the threat of force. This time, enforcement measures were introduced, allowing for economic sanctions and military interventions authorized by the UN Security Council.

Although geopolitical realities have at times prevented decisive action—such as the inability of the UN to stop Russia’s annexation of Crimea in 2014—the overall success of this framework is undeniable. According to legal scholars Oona Hathaway and Scott Shapiro from Yale University, the post-1928 period has witnessed a dramatic reduction in wars of territorial conquest. Their research shows that while before 1928, the world saw an average of 295,000 square kilometers conquered per year, this number dropped significantly after the establishment of legal prohibitions on war.

The Role of Humanitarian Law in War

While international law has sought to prevent wars, it has also worked to humanize them when they do occur. The Geneva Conventions, first signed in 1864 thanks to the efforts of Henry Dunant and the Red Cross, laid the foundation for humanitarian law. These agreements established protections for wounded soldiers, prisoners of war, and civilians, setting a legal precedent for ethical conduct during conflicts.

Over the years, these principles have been expanded, with additional protocols addressing the use of biological and chemical weapons, landmines, and indiscriminate bombing. The aim has always been to mitigate human suffering, even in the midst of war. Critics, including some pacifists, have argued that by making war less brutal, these laws inadvertently make it more acceptable. However, studies suggest that far from encouraging conflict, humanitarian laws impose burdens on military forces, limiting their ability to conduct unrestricted warfare.

A World Where War is No Longer the Norm

The prohibition of war and the development of international law have not eradicated armed conflict, but they have fundamentally changed its nature. Large-scale wars of conquest, once a common feature of global politics, have become rare. Nations now face international legal and diplomatic consequences for aggression, making war a far less viable option than it once was.

While conflicts persist, the global legal framework has made significant strides in limiting their scope and brutality. By criminalizing war, enforcing humanitarian standards, and strengthening international accountability, the world has moved toward a more stable and just order.

The vision laid out in 1928, though imperfect, continues to shape modern diplomacy and conflict resolution.

Reference: This article was inspired by "L?sst sich der Krieg z?hmen? Die historische Bilanz ist gar nicht so düster" by Daniel Di Falco, published in NZZ Geschichte, February 2025.

https://www.nzz.ch/wissenschaft/laesst-sich-der-krieg-zaehmen-die-historische-bilanz-ist-gar-nicht-so-duester-ld.1869026