Robert H. Jackson served as the United States Chief of Counsel at the Nuremberg trials, where he negotiated the tribunal’s governing charter, defined the categories of international crimes the defendants would face, built the prosecution around captured Nazi documents, and delivered the opening statement that framed the entire proceeding. President Harry S. Truman appointed him through Executive Order 9547 on May 2, 1945, pulling him away from his seat as an Associate Justice of the United States Supreme Court to lead the American effort against the major Nazi war criminals.1Truman Library. Executive Order 9547
Why Truman Chose Jackson, and Why Jackson Took the Case
When Truman tapped Jackson in May 1945, the war in Europe had just ended and Allied officials were divided on what to do with captured Nazi leaders. Some favored summary execution. Jackson argued the opposite: a formal trial was essential, both to document what had happened and to establish that law, rather than raw power, would govern the aftermath.
Taking the assignment required a leave of absence from the Supreme Court, an extraordinary step that reflected how seriously Jackson and Truman treated the task.1Truman Library. Executive Order 9547 Jackson had served as Solicitor General and Attorney General under President Franklin D. Roosevelt before joining the Court in 1941, so he brought both prosecutorial experience and judicial standing to the role.2Supreme Court Historical Society. Robert H Jackson 1941-1954
Negotiating the London Charter
Before any trial could begin, the four Allied powers needed to agree on what to charge, what procedures to follow, and how to structure a tribunal that could claim legitimacy. During the summer of 1945, Jackson worked with representatives from Great Britain, France, and the Soviet Union to negotiate the London Agreement and its annexed Charter, which established the International Military Tribunal. Jackson signed the agreement on behalf of the United States.3The Avalon Project. London Agreement of August 8th 1945
Reconciling four legal traditions was the central difficulty. The American and British teams operated from common law systems built on adversarial proceedings and cross-examination. The French and Soviet delegations came from civil law and Soviet legal traditions with different assumptions about the role of judges, the admissibility of evidence, and the rights of the accused. Jackson pushed for adversarial trial procedures, open presentation of evidence, and robust defense rights. The resulting document drew from all four systems but leaned heavily toward common law principles of due process.
The Crimes Jackson Put on Trial
Article 6 of the Charter defined three categories of crimes within the tribunal’s jurisdiction, each carrying individual criminal responsibility.4International Committee of the Red Cross. Charter of the Nuremberg Tribunal 1945 – Article 6
Crimes against peace covered the planning, preparation, initiation, or waging of a war of aggression, or a war in violation of international treaties. Jackson considered this the supreme international crime because it encompassed all the evil that followed from it. War crimes covered violations of the laws and customs of war, including mistreatment of prisoners, killing of hostages, plunder, and wanton destruction of cities not justified by military necessity. Crimes against humanity covered murder, extermination, enslavement, deportation, and persecution on political, racial, or religious grounds committed against civilian populations, whether before or during the war.
The indictment added a fourth count: conspiracy to commit the crimes outlined in the Charter. Conspiracy was familiar in Anglo-American law but largely foreign to continental European legal systems. Jackson insisted on its inclusion because it allowed the prosecution to treat the Nazi leadership as participants in a single coordinated criminal enterprise rather than as isolated actors.5The National WWII Museum. The London Agreement and Charter A defendant who helped plan the war could be held accountable for atrocities carried out by others under the same plan, even if the defendant never personally ordered a specific killing.
Building the Case on Documents
Jackson made a deliberate strategic choice that shaped the entire prosecution: he relied overwhelmingly on captured Nazi documents rather than live witness testimony. The American team brought roughly 100,000 seized German documents to Nuremberg, examined millions of feet of captured film, and compiled 25,000 still photographs.6GovInfo. Justice Stephen Breyers Address for the 1995 Days of Remembrance Ceremony
The reasoning was both tactical and philosophical. Witnesses could be discredited, their memories questioned, their motives attacked. Documents written by the defendants themselves carried a different weight. When a planning memo for the invasion of Poland bore a defendant’s signature, no cross-examination could undo it. The strategy also served Jackson’s larger goal of creating an irrefutable historical record. The prosecution team described the approach as one that would “rely on documentary evidence, eschewing possibly volatile eyewitness testimony.”7The National WWII Museum. Justice Robert H Jacksons Opening Statement at Nuremberg
The Opening Statement
Jackson delivered his opening statement on November 21, 1945, the second day of the trial. The address ran more than three hours and remains one of the most cited speeches in the history of international law.7The National WWII Museum. Justice Robert H Jacksons Opening Statement at Nuremberg It spoke to two audiences at once: the four judges deciding the case and the watching world that needed to understand why a trial mattered more than a firing squad.
Jackson opened by framing the moral stakes. He told the tribunal that the trial represented “one of the most significant tributes that Power has ever paid to Reason.” The victorious nations, having captured the enemy’s leaders, chose to submit their case to judgment rather than simply impose punishment. This was his answer to the charge of victor’s justice. If the Allies wanted revenge, they had the military power to take it. Choosing a trial meant accepting the possibility, however theoretical, that the tribunal might acquit.
The speech then turned to the evidence itself. Jackson walked the tribunal through the documentary record methodically, letting the defendants’ own words carry the argument. He described the premeditated planning of aggressive war, the systematic persecution of Jews and other groups, the deliberate violations of treaty obligations, and the scale of the atrocities committed across occupied Europe. He warned that “the wrongs which we seek to condemn and punish have been so calculated, so malignant, and so devastating, that civilization cannot tolerate their being ignored, because it could not survive their being repeated.”
The Cross-Examination of Göring
If the opening statement was Jackson’s finest moment at Nuremberg, his cross-examination of Hermann Göring in March 1946 was his most difficult. Göring was intelligent, combative, and unrepentant. He treated the witness stand as a platform to defend the Nazi regime, delivering long speeches in response to narrow questions and probing for weaknesses in the prosecution’s framing.
Jackson’s background worked against him. He was a brilliant legal thinker and a gifted appellate advocate, but he had limited experience with hostile witnesses in adversarial cross-examination. Göring exploited this, nitpicking questions, redirecting answers, and refusing to be pinned down. Contemporary observers noted that Jackson struggled to control the witness. The British prosecutor Sir David Maxwell Fyfe, who followed Jackson, took a different approach by asking tight, factual questions that left Göring little room to maneuver.
The episode is sometimes called one of the worst cross-examinations in legal history, but that verdict oversimplifies what happened. Jackson’s documentary strategy meant the case against Göring did not depend on admissions extracted during cross-examination. The documents had already done their work. Göring was convicted on all four counts and sentenced to death. He killed himself with a cyanide capsule the night before his scheduled execution.
Answering Victor’s Justice and Retroactivity
The most persistent criticism of the tribunal was the charge of victor’s justice, the argument that the trial was nothing more than the conquerors punishing the conquered under a legal veneer. Closely related was the retroactivity objection, the claim that the defendants were being tried for conduct not codified as international crimes when they committed it.
Jackson’s primary response was structural rather than rhetorical. He insisted that the trial itself demonstrate fairness. The defendants had access to counsel of their choosing. Under the tribunal’s rules, each defendant had the right to conduct his own defense or to have the assistance of an attorney, and the tribunal would appoint counsel for any defendant who did not arrange his own.8The Avalon Project. Nuremberg War Crimes Trial – Rules of Procedure Defendants received the indictment in German, had access to the prosecution’s documentary evidence, could call witnesses, and were permitted to testify in their own defense. Several did, including Göring, who spoke for days.
On retroactivity, Jackson argued that the Kellogg-Briand Pact of 1928 and other international treaties had already outlawed aggressive war, meaning the defendants knew their conduct violated international obligations. The novelty was not the prohibition but the enforcement mechanism. He also pointed out, bluntly, that the alternative to a trial was summary execution, and that no defendant would prefer the alternative to the process they were criticizing.
What Nuremberg Produced
The tribunal delivered its judgment on September 30 and October 1, 1946. Twelve defendants were sentenced to death by hanging, including Joachim von Ribbentrop, Hans Frank, Alfred Rosenberg, Julius Streicher, and Göring. Three received life imprisonment. Four received prison terms of ten to twenty years. Three were acquitted and released.9United States Holocaust Memorial Museum. Nuremberg Trial Verdicts The acquittals mattered as much as the convictions for Jackson’s purposes. A tribunal that acquits some defendants is harder to dismiss as a show trial.
In 1950, the United Nations International Law Commission formalized the legal concepts established at Nuremberg into seven principles that became foundational to international criminal law.10United Nations International Law Commission. Principles of International Law Recognized in the Charter of the Nuremberg Tribunal and in the Judgment of the Tribunal 1950 The first principle established that any person who commits an act constituting a crime under international law bears personal responsibility and is liable to punishment. The third extended this: acting as a head of state or government official provides no shield from accountability. The fourth addressed the defense of superior orders, holding that following a government’s or a commander’s orders does not relieve a person of responsibility if a moral choice was possible.
These principles did not remain abstract. They shaped the Rome Statute that established the International Criminal Court in 2002. Individual criminal responsibility appears in Article 25. The irrelevance of official capacity is codified in Article 27. Superior orders are addressed in Article 33. The Nuremberg concept of crimes against peace is reflected in the Rome Statute’s provision on the crime of aggression in Article 8 bis. The right to a fair trial, which Jackson fought to embed in the Nuremberg proceedings, appears in Article 67. The principles also provided the legal foundation for the ad hoc tribunals created in the 1990s for the former Yugoslavia and Rwanda.
Jackson returned to the Supreme Court after the trial and served until his death on October 9, 1954. His Nuremberg legacy is complicated. The Soviet judge sat in judgment while his own government’s crimes went unexamined. The retroactivity objection was never fully resolved so much as overridden by the weight of the atrocities. The cross-examination of Göring exposed the limits of his courtroom skills. The core achievement endures: the idea that individuals who wage aggressive war and commit atrocities against civilians can be held personally accountable under international law, regardless of their rank, their orders, or the sovereignty of the state they served.