Signing the Agreement of London, August 8, 1945
Credit: Charles Alexander, Office of the United States Chief of Counsel. Harry S. Truman Library & Museum.

The London Agreement created the IMT and its Charter. The Charter of the International Military Tribunal – Annex to the Agreement for the prosecution and punishment of the major war criminals of the European Axis – defined the laws and procedures by which the Nuremberg trials were to be conducted.

Robert H. Jackson's Notes

On 8 August 1945 we signed the agreement, as I was authorized to do on behalf of the United States, and it was announced to the world. Up to that time there had been some press rumors that we were having difficulties in arriving at it. We had frankly admitted we had, but there had been no exploitation of our differences.

I may sat that the chief critics of it were a few international lawyers who simply could not adjust themselves to the idea that he world had moved since the time of the Hague Conventions and that the treaties outlawing war and renouncing it as an instrument of policy had made a change in the old doctrine that it always is legal for a country to go to war for aggressive ends if it pleased its interests to do so.

The Reminiscences of Robert H. Jackson Columbia Univ. Oral History Research Office, 1955