The Tokyo Tribunal, also less often referred to as the International Military Tribunal for the Far East (IMTFE), tells the story of how 28 Japanese civilian and military leaders conspired to wage an aggressive war against the Allied powers in the period from 1928 to 1945. There is much more to it than the Japanese leaders’ punishment through judicial mechanism. The Tokyo Tribunal bears potential to illuminate on the important concepts of international criminal justice and international order, which could give a whole new perspective on this, at various levels, important judicial mechanism.

Together with its European counterpart, or the International Military Tribunal (IMT) at Nuremberg, it represents the first institutional manifestation of the idea that war can amount to not only an illegal act triggering international state responsibility, but also a criminal act allowing for individual criminal responsibility of high state and military representatives. The premise that the war crimes tribunals can constitute an integral cooperative component of the post-World War II international order establishing process and, furthermore, deter future aggression had been tested by the two tribunals. The results were, to say the least, mixed as this book intends to demonstrate.

At the heart of the IMTFE is the crime of aggression, contrary to modern international criminal tribunals whose material jurisdiction exclusively focuses on war crimes, crimes against humanity, and what has been often labeled as the ultimate crime in international law, genocide. Transitional justice constitutes a panoply of mechanisms for dealing with international crimes, international criminal tribunals being only one of them. It is important to mention hybrid courts and truth commissions as other available processes for dealing with the responsibility for crimes committed in post-conflict societies. International criminal justice is not a permanent mechanism; international criminal law has been applied only sporadically in the postwar period by the International Criminal Tribunal for ex-Yugoslavia (ICTY) and the International Criminal Tribunal for Rwanda (ICTR), which are its two most notorious examples.

In 2002, with the entry into force of the Rome Statute establishing the International Criminal Court (ICC), international criminal justice was given a more permanent character. However, the ICC does not have universal reach as many states regularly involved in warfare around the world are not its members (the US, China, Russia, Israel). While the ICC is highly consensual in character, the above-mentioned ad hoc international criminal tribunals (ICTs) were imposed on states by UNSC (UN Security Council) resolutions. Also, the Court’s activities are subjected to the UNSC that can intervene to postpone or stop the investigation or trial, for six months renewable, if it deems that a specific trial is obstructing the peace process. Contrary to the above-mentioned ad hoc mechanisms, the ICC has material jurisdiction over the crime of aggression since 2017; however, as the crime remains poorly defined and member states can prevent their statesmen or military from facing charges by using the available “opt out”¹ clause, it remains largely unused. This strongly shows that what Chief Prosecutor Joseph Keenan at the IMTFE called “the supreme international crime,”² referring to the crime against peace or the crime of aggression, has remained dormant and highly controversial to the present day.

The Tokyo Tribunal, which is the exclusive focus of this book, was officially established on May 3, 1946. Symbolically, the rooms of the Imperial War Ministry that were not so long ago the place where Japanese leaders made war plans were remodeled to host the historic Tribunal to prosecute 28 Japanese military and civilian leaders for waging aggressive war in the Asia-Pacific region. Two perspectives emerge. The first one is the perspective of the victor and, at the same time, victim nations which did not observe these selected Japanese politicians and military as statesmen, but as criminals who ought to be severely punished. Above all, they were targeted for planning, waging, and instigating aggressive war and war crimes inflicted upon prisoners of war and civilians throughout the Japanese Empire. The second one is the perspective of defendants, mostly prominent figures in Imperial Japan, who felt that they did their best to discharge official duties and to faithfully serve Japan’s national interest. In their eyes, they failed to win the war for which they were being prosecuted. To them, the issues lay in their miscalculated political and strategic decisions, but not guilt related to the violation of morals, ethics, and international rules that they did not know about.

The Tokyo Tribunal is a part of the Allied powers’ occupation policy. The early occupation plan was articulated around disarmament, demilitarization, and democratization which would allow Japan to reintegrate a newly created postwar international order, open and multilateral in nature.³ Its jurisdiction was imposed upon defeated Japan that signed the Instrument of Surrender on September 2, 1945, by which it accepted the unconditional surrender and military occupation which was to be led by the Supreme Commander Douglas MacArthur, on behalf of the 11 Allied powers (the US, Britain, Australia, Soviet Union, the Netherlands, New Zealand, Canada, France, China, Philippines, and India). These nations were all represented at the Tribunal both within its prosecution section and panel of judges. A legal basis for the war crimes program in Japan is contained in the Potsdam Declaration of July 26, 1945, which read that stern justice should be meted out to all war criminals. At that time, the Allies’ war crimes trials were already under way in Germany which put the pressure for a similar program to be implemented in Japan. It was expected that trials in Japan would start as soon as the roadmap had been paved by the German experience. The IMTFE Charter was unilaterally proclaimed by the Supreme Commander on January 19, 1946. Legal precedents such as that the aggressive war was an international crime triggering individual criminal responsibility of heads of states and their military had already been agreed upon in fastidious rounds of negotiations between the four allies in London in July 1945.

These were groundbreaking changes for international law and exercise of traditional statecraft which considered war to be a political act of state, not a criminal one. Present-day mechanisms of international criminal justice have become mainly preoccupied with the application of humanitarian regimes that regulate state and non-state actors’ behavior in times of both war and peace. These judicial mechanisms particularly excelled at further development and refinement of crimes against humanity, war crimes, and genocide, thus addressing mass atrocity. Post-Cold War era’s predominant legal, political, and societal discourse displays unquestionable support for respect and, when political willingness is present, the application of human rights and humanitarian regimes. Although World War II had the character of total war in which the brutalization of entire societies and cruelty of its participants gained momentum, the Allies were using these as a moral pretext to address what was considered at that time a greater issue—the individual responsibility for starting the aggressive war in both Japan and Germany. The deficit of international humanitarian norms was not at stake. The laws of war had existed but were ignored and downplayed as inept to respond to the complexity and scale of events which aimed at the utter destruction of the enemy.

Invariably, in the words of Brian Orend, every war is a “nasty business which, ultimately, calls forth more vice than virtue,”⁴ and this applies to the case in point—the Pacific War. Despite the normative distinction between aggressive and defensive wars, ethically, such differentiations do not stand—if the ultimate test of morality is killing, then every war is immoral.⁵ At the outset, it is necessary to clarify that this book does not question the veracity of Japanese atrocities nor exculpate or justify the behavior of wartime leaders in Imperial Japan. Rather, by adopting a posture of “moral minimalism,” it remains focused on understanding the mentalité, political decisions, and international dynamics of the postwar period in which the prosecution of crimes of aggressive war or crimes against peace took place.

Contrary to the trial records of the International Military Tribunal at Nuremberg that were almost immediately published by its Secretariat in separate volumes from 1947 to 1949, the IMTFE records were lying in obscurity until the 1980s. In addition to this, academic debate was clearly distinguished between legal scholars and historians. Since 2008, the effort to reconcile the gap between the two disciplines and their respective methods and objectives has been reflected by publications where legal scholars and historians worked together⁶ on treating important aspects of the Tribunal as it is, after all, both a historic and a legal event.

The classic works about the Tokyo Tribunal aim to assess the quality of justice at Tokyo and lie between the extreme views that qualify its justice as “victors’ justice” or “justice of civilization.” The volume Victors’ Justice by Richard Minear published in 1971 offers a fierce critique of the Tribunal’s legal postulates that were straightforwardly violated by American engagement in the Vietnam War. Minear rejects the legality of norms and procedural rules that were created ex post facto by the victorious Allies in order to get rid of Axis leaders and assign the ultimate responsibility for the Pacific War to the Japanese top brass. The selection of the members of the Tribunal was not merit based, but rather politically motivated to create a group of individuals who would be willing to carry out the postwar goals set by their respective governments and the Supreme Commander Douglas MacArthur—thus being prejudicial to the impartiality of justice and due process of law. He strongly argued that victors’ justice was blind to similar atrocities committed and brutality used by the Allied powers to achieve victory. The rationale behind the Tribunal required 17 years of Japanese history to be rewritten in order to fit the dominant narrative of Japan’s conspiracy to wage aggressive war, which resulted in history being profoundly flawed and simplified. In the author’s words, the historical complexities leading towards the Pacific War could not have been grasped by the legalistic framework.

On the opposite spectrum of Minear’s reasoning stands the work of Japanese historian Kentarō Awaya, whose book Tōkyō saiban e no...