The Japanese war crimes trials after World War II were a two-tier set of proceedings: a central International Military Tribunal for the Far East in Tokyo that tried twenty-eight senior political and military leaders, and hundreds of separate national military trials across Asia and the Pacific that tried thousands of lower-ranking personnel for specific atrocities. The Tokyo tribunal opened on April 29, 1946, and finished reading its judgment on December 12, 1948, making it one of the longest war crimes trials in history.1Peace Palace Library. The Tokyo Trial Seven defendants were hanged, many more imprisoned, and several of the most serious wartime offenses were quietly left out of the courtroom altogether.
How the Trials Were Organized
General Douglas MacArthur, acting as Supreme Commander for the Allied Powers, issued a special proclamation on January 19, 1946, establishing the International Military Tribunal for the Far East (IMTFE) and approving its Charter.2International Military Tribunal for the Far East Charter. International Military Tribunal for the Far East Charter Unlike the Nuremberg tribunal, which was created by agreement among four Allied powers, the IMTFE was established by MacArthur’s proclamation alone.3Office of the Historian. The Nuremberg Trial and the Tokyo War Crimes Trials
Eleven judges sat on the bench, one from each nation that had signed Japan’s instrument of surrender or had been deeply affected by the war: the United States, the Soviet Union, the United Kingdom, China, France, the Netherlands, Canada, Australia, New Zealand, India, and the Philippines.4The National WWII Museum. Tokyo War Crimes Trial Sir William Webb of Australia served as president. Joseph B. Keenan, appointed by President Truman in November 1945, led the prosecution.5U.S. Department of Justice. Joseph B. Keenan
The Charter reached crimes committed across every territory Japan had occupied, from the 1931 invasion of Manchuria through the 1945 surrender. That longer timeframe set the Tokyo proceedings apart from Nuremberg, which addressed a shorter span of German aggression.3Office of the Historian. The Nuremberg Trial and the Tokyo War Crimes Trials
The Three Classes of Crimes
The Charter defined three categories, borrowed almost word for word from Nuremberg.
- Class A, Crimes Against Peace: planning, preparing, or launching wars of aggression in violation of international treaties. This was the most conceptually ambitious charge, because it held individuals personally accountable for what had traditionally been treated as a collective act of the state.6The Avalon Project. Charter of the International Military Tribunal
- Class B, War Crimes: violations of the laws and customs of war, including mistreatment of prisoners, killing of hostages, and destruction not justified by military necessity.
- Class C, Crimes Against Humanity: large-scale atrocities against civilian populations, including enslavement, deportation, and persecution on political or racial grounds.
Class A targeted the architects of the war. Class B and C reached the people who carried out policies on the ground, from camp commanders who starved prisoners to officers who ordered massacres of civilians. Many regional defendants faced both B and C charges together.
The Tokyo Trial of Senior Leaders
Twenty-eight defendants were charged with fifty-five separate counts covering all three categories.1Peace Palace Library. The Tokyo Trial Former Prime Minister Hideki Tojo was the most prominent among them. The others included former foreign ministers, military commanders, and senior government officials who had directed Japan’s expansion across Asia.
Three defendants never reached judgment. Former Foreign Minister Yosuke Matsuoka and former Navy Chief of Staff Osami Nagano died of natural causes during the trial. Ultranationalist propagandist Shumei Okawa was found mentally unfit, and charges against him were dropped.1Peace Palace Library. The Tokyo Trial That left twenty-five who received verdicts.
The prosecution introduced thousands of documents: cabinet minutes, telegrams, military orders, and diplomatic correspondence used to reconstruct decision-making inside the Japanese government. The 1931 invasion of Manchuria and the chain of escalating aggression that followed received central attention, as did the planning for the December 1941 attack on Pearl Harbor. The reading of the final judgment alone ran from December 4 to 12, 1948.1Peace Palace Library. The Tokyo Trial
Sentences at Tokyo
Seven defendants were sentenced to death by hanging:1Peace Palace Library. The Tokyo Trial
- Hideki Tojo, Prime Minister during most of the war
- Koki Hirota, former Prime Minister and the only civilian among those executed
- Kenji Doihara, intelligence officer instrumental in the Manchuria takeover
- Seishiro Itagaki, War Minister and Manchuria conspirator
- Iwane Matsui, commander during the Nanjing Massacre
- Akira Muto, Chief of Staff in the Philippines during widespread atrocities
- Heitaro Kimura, Vice War Minister and commander in Burma
All seven were executed at Sugamo Prison on December 23, 1948. Sixteen defendants received life imprisonment. Former Foreign Minister Mamoru Shigemitsu received seven years, and former Foreign Minister Shigenori Togo received twenty years; Togo died in prison in 1949.
The Regional Class B and C Trials
While Tokyo dealt with the leadership, a wider network of proceedings prosecuted lower-ranking officers and enlisted personnel for field atrocities and the administration of occupied territories. These were run by national military commissions set up by the United States, Australia, Britain, China, France, the Netherlands, and the Philippines.7Anzac Portal. War Crimes Trials for the Japanese After World War II Trials were held in Manila, Singapore, Yokohama, Rabaul, Hong Kong, and other locations, deliberately close to where the crimes occurred so evidence and witnesses would be at hand.
Two episodes recurred across many trials. The Bataan Death March of April 1942, in which thousands of American and Filipino prisoners of war died during a forced march, led to the prosecution and execution of Lieutenant General Masaharu Homma, the Japanese commander responsible.8The United States Army. History of the Bataan Death March The construction of the Burma-Thailand Railway, where Allied prisoners and tens of thousands of Asian forced laborers died under brutal conditions, generated extensive prosecutions; Australian courts alone tried sixty-two individuals for crimes committed on that railway.9Anzac Portal. Japanese and Korean Soldiers on the Burma-Thailand Railway
Across all regional venues, roughly 920 death sentences were handed down against Class B and C defendants, and thousands more received prison terms from a few years to life. The disparity in numbers compared to Tokyo reflected the different nature of the charges: Tokyo convicted leaders for decisions that led to war, while the regional courts convicted individuals for specific acts of violence, starvation, and torture.
Who Was Not Prosecuted
Several conspicuous absences shaped the trials’ legacy as much as the convictions did.
Emperor Hirohito
Emperor Hirohito was never charged. MacArthur warned Washington that indicting him would “cause a tremendous convulsion among the Japanese people” and could require a million occupation troops to maintain order.10Office of the Historian. Foreign Relations of the United States, 1946, The Far East, Volume VIII He argued the Emperor was a unifying symbol and that removing him risked driving the population toward communism. The IMTFE Charter, unlike the Nuremberg Charter, omitted any provision allowing the prosecution of heads of state.
Unit 731 and Biological Warfare
Japan’s biological weapons program, centered on Unit 731 under General Shiro Ishii, conducted experiments on live human subjects in Manchuria. U.S. authorities granted immunity to its leaders. Internal U.S. government documents show the State-War-Navy Coordinating Committee concluded “the value of Japanese BW information outweighs war crimes prosecution” and pressed for immunity in exchange for full disclosure of research data.11National Archives. Select Documents on Japanese War Crimes The Soviet Union prosecuted twelve Unit 731 personnel at the 1949 Khabarovsk trials; the United States and other Western allies dismissed those proceedings as communist propaganda.
Sexual Slavery
The system of forced sexual slavery, in which tens of thousands of women across occupied Asia were coerced into servicing Japanese troops, went virtually unaddressed at the Tokyo Trial. The gap would not receive formal international judicial attention until decades later.
The Pal Dissent and the Victor’s Justice Critique
The Tokyo verdict was not unanimous. Justice Radhabinod Pal of India voted for the acquittal of every defendant on every count. He rejected the legal validity of “crimes against peace,” calling the concept an invention “for the satisfaction of a thirst for revenge,” and dismissed the prosecution’s claim that a conspiracy to wage aggressive war had existed within the Japanese leadership since 1928.12The National WWII Museum. Justice Radhabinod Pal and the Tokyo Tribunal
Pal placed Japanese conduct within the context of European colonialism in Asia and singled out the atomic bombings of Hiroshima and Nagasaki as among the most criminal acts of the war. He did acknowledge that Japanese forces had committed genuine atrocities, including the Nanjing Massacre, but argued those should have been handled strictly as Class B and C offenses rather than folded into a broader conspiracy charge.
A broader “victor’s justice” criticism followed the trials from the start. Allied conduct, including the firebombing of Japanese cities and the use of nuclear weapons, was never examined. No Allied personnel faced charges. The bench was composed entirely of judges from the victorious nations, with no neutral representation.
The Cold War Reversal and Early Releases
By late 1947, the United States had begun a “reconsideration of occupation policies” driven by an economic crisis in Japan and growing fears about communism in Asia. This “reverse course” shifted American priorities from punishment and reform to economic rehabilitation and strategic partnership.13Office of the Historian. Occupation and Reconstruction of Japan The communist victory in China and the outbreak of the Korean War in 1950 accelerated the change. No further Class A prosecutions were pursued after Tokyo concluded, even though additional suspects had been identified.
The 1951 San Francisco Peace Treaty formally ended the occupation and restored Japanese sovereignty while requiring Allied consent for any parole or commutation of war crimes sentences. Over the 1950s, the convicted prisoners were steadily released. By 1957, all eleven surviving Class A war criminals had been released and placed on parole.14Office of the Historian. Foreign Relations of the United States, 1955-1957, Japan, Volume XXIII Australia, the last Allied nation still detaining Japanese war criminals, completed its releases by mid-1957. Some formerly convicted individuals went on to hold prominent positions in postwar Japanese society and government.
What the Trials Established, and What They Left Unresolved
The trials set out principles that outlived the proceedings themselves: that individuals, including senior government leaders, could be held criminally responsible for waging aggressive war; that “following orders” was not a defense for atrocities; and that the international community could convene courts to enforce these norms. Together with Nuremberg, Tokyo laid the groundwork that eventually led to permanent institutions such as the International Criminal Court.
The same proceedings carried contradictions that still shape how they are remembered. Shielding the Emperor, granting immunity to biological weapons researchers, omitting sexual slavery from prosecution, releasing convicted war criminals under Cold War pressure, and refusing to examine Allied conduct all suggested that justice was applied selectively. The tensions have made the trials a continuing source of historical and diplomatic friction, particularly between Japan and its neighbors in China and Korea, where the question of whether Japan has adequately acknowledged its wartime conduct remains contested.