The correct answer to this open question is the following.
What Benjamin Ferencz meant when he says the Nuremberg Trials established the principle of "the rule of law rather than rule of force, " was that during the Nuremberg Trials against the German military officials, there was no rule of force or vengeance against them just for many atrocities they committed during World War II. Instead, a full and proper trial was established to judge them under the law.
During the Nuremberg Trials, Benjamin Ferencz was a prosecutor that supported the application of strict laws to judge the Germans. He also supported the International Criminal Court.
Ferencz was the main United States prosecutor in the case "Einsatzgruppen."