A preliminary U.S. government assessment reviewed by Reuters asserts the diary could offer new insight into meetings Rosenberg had with Hitler and other top Nazi leaders, including Heinrich Himmler and Herman Goering. It also includes details about the German occupation of the Soviet Union, including plans for mass killings of Jews and other Eastern Europeans.

“The documentation is of considerable importance for the study of the Nazi era, including the history of the Holocaust,” according to the assessment, prepared by the United States Holocaust Memorial Museum in Washington. “A cursory content analysis indicates that the material sheds new light on a number of important issues relating to the Third Reich’s policy. The diary will be an important source of information to historians that compliments, and in part contradicts, already known documentation.”

How the writings of Rosenberg, a Nazi Reich minister who was convicted at Nuremberg and hanged in 1946, might contradict what historians believe to be true is unclear. Further details about the diary’s contents could not be learned, and a U.S. government official stressed that the museum’s analysis remains preliminary.

But the diary does include details about tensions within the German high-command – in particular, the crisis caused by the flight of Rudolf Hess to Britain in 1941, and the looting of art throughout Europe, according to the preliminary analysis.