I recently came across a letter that President Truman had wrote to Henry Stimson when Stimson was resigning from the Secretary of War position dated September 19, 1945. In that letter Truman stated
No one saw more clearly than you how the shape of things to come was foreshadowed in the Japanese aggression in Manchuria. Historians will speculate whether the holocaust which spread over the whole world within a decade could not have been prevented had your advice as Secretary of State been followed.
I'm not too familiar with the historiography on the run up to the Holocaust, but was Truman on the right track anticipating this scholarly debate or was Stimson's contribution not important enough to consider?
Edit: I would post a scan of the letter but it's from the Truman library archives and I'm not sure if that's allowed.
You are misunderstanding the term "holocaust," as used in this context. Truman is writing about the world-wide catastrophe, that is, the war itself. He is not using the term with a capital "H" to signify the mass murder of Jews.