From Nuremberg to The Hague: How WWII Trials Shaped Modern International Law

by Joseph Davies

The 20th century, and WWII in particular, marked a period of rapid military development where states and their populations witnessed war on an unprecedented scale. Following WWII, the Nuremberg and Tokyo trials ushered in a transformative era for international law. Their legacies profoundly shaped legal frameworks for decades.
By 1907, the Hague Conventions had established foundational rules for the conduct of warfare. These agreements, along with the 1929 Geneva Convention, defined violations of the laws of war, addressing the treatment of soldiers, sailors, and civilians during conflicts. However, as WWII ended, the Allies found these frameworks inadequate for the atrocities committed by Nazi Germany and Imperial Japan. Consequently, the London Charter of 1945 established the International Military Tribunal, introducing two new categories of war crimes to prosecute war criminals: Crimes against Peace and Crimes against Humanity.

Crimes against Peace condemned wars prepared or waged aggressively in violation of international treaties. This charge was significant, as it challenged national sovereignty by asserting that international law could hold state leaders accountable. For example, Nazi official Hermann Göring was tried at Nuremberg, unprotected by Germany’s autonomy. However, the charge sparked controversy, particularly at the Tokyo Trials. Japanese defense lawyers and Justice Radhabinod Pal argued that Japan’s expansionism aimed to liberate East Asia from European colonialism, not to wage aggressive war. Critics, including historians, have labeled the Tokyo Trials as “victors’ justice,” noting that Allied atrocities and imperialism went unpunished and that Emperor Hirohito was excluded from prosecution to ensure Japan’s post-war stability, a decision that fueled debates over impartiality. Despite these controversies, prosecuting Crimes against Peace at Nuremberg and Tokyo established that aggressive war violates international law, overriding national sovereignty.


Crimes against Humanity, conversely, aimed to protect civilian populations during both wartime and peacetime, even from their own governments. This allowed Nazis to be held accountable for systematic atrocities, such as the Holocaust, committed against their own citizens before military conquests began. Although the term “genocide” was not codified at Nuremberg, the tribunal’s recognition of systematic oppression as a war crime influenced the 1948 Genocide Convention. Nuremberg’s legal framework continues to resonate, notably through the Rome Statute, which criminalizes atrocities, including genocide.

After the Cold War, the collapse of Yugoslavia prompted the establishment of the International Criminal Tribunal for the former Yugoslavia (ICTY) in 1993, the first international war crimes court since the Tokyo Trials (1946–1948). Seated in The Hague, the ICTY indicted 161 individuals on four types of charges: Crimes against Humanity, genocide, war crimes, and violations of the laws or customs of war, as defined by the 1948 Genocide Convention and the Geneva Conventions. The ICTY broke new ground by recognizing rape as a Crime against Humanity, notably in Prosecutor v. Kunarac (2001). Similarly, the International Criminal Tribunal for Rwanda (ICTR), established in 1994 following the Hutu government’s genocide of Tutsis, prosecuted war criminals for Crimes against Humanity and genocide. Drawing on Nuremberg’s legal framework, the ICTR was pivotal for applying international criminal law to a non-international conflict, a significant evolution from Nuremberg’s focus on state-sponsored atrocities, as it addressed the internal Rwandan genocide. The ICTR also secured the first genocide conviction in 1998 (Prosecutor v. Akayesu), cementing the legal precedent for prosecuting genocide.
Despite the slow development of international courts during the Cold War, the 1990s marked a period of significant change with the ICTY and ICTR. Together, these tribunals refined the legal standards set by the London Charter, Nuremberg, and Tokyo, demonstrating the ongoing evolution of international law. In 1998, the Rome Statute established the International Criminal Court (ICC), which, since coming into force in 2002, has enforced the illegality of Crimes against Humanity, genocide, war crimes, and the crime of aggression (codified in 2010). The ICC remains a subject of debate, particularly regarding non-ratifying states and its role in 21st-century conflicts.
Today, while international law remains evolving and contested, the frameworks established by Nuremberg and Tokyo retain their significance. Their legacies are evident in the Rome Statute and the principle that sovereign nations are subject to international standards of justice, despite ongoing disputes over enforcement and efficacy.

 
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