The entry of the U.S. into the War is also crucial to the time-frame proposed by Christian Gerlach, who argued in his 1997 thesis,[122] that the Final Solution decision was announced on 12 December 1941, when Hitler addressed a meeting of the Nazi Party (the Reichsleiter) and of regional party leaders (the Gauleiter).[123][a] The day after Hitler's speech, on 13 December 1941 Joseph Goebbels wrote in his diary:[125]
The Mossad’s South American station chief cabled the headquarters in Israel: “Zvi saw on Gerhard’s farm a person who in form, height, age and dress looks like Mengele.” It later turned out that he was indeed Mengele. Speaking to me in 1999, Aharoni told me: “We were in an excellent mood. I was certain that in a little while we would be able to bring Mengele to Israel to be tried.”
The Yad Vashem Law authorizes Yad Vashem "to confer honorary citizenship upon the Righteous Among the Nations, and if they have died, the commemorative citizenship of the State of Israel, in recognition of their actions". Anyone who has been recognized as "Righteous" is entitled to apply to Yad Vashem for the certificate. If the person is no longer alive, their next of kin is entitled to request that commemorative citizenship be conferred on the Righteous who has died.
G. Aly, "Final Solution": Nazi Population Policy and the Murder of the European Jews (1999); C.R. Browning (with contributions by J. Matthäus), The Origins of the Final Solution: The Evolution of Nazi Jewish Policy, September 1939- March 1942 (2004); R. Hilberg, The Destruction of the European Jews (20033); P. Longerich, Politik der Vernichtung. Eine Gesamtdarstellung der nationalsozialistischen Judenverfolgung (1998).

In February 2010, a 180-page volume of Mengele's diary was sold by Alexander Autographs at auction for an undisclosed sum to the grandson of a Holocaust survivor. The unidentified previous owner, who acquired the journals in Brazil, was reported to be close to the Mengele family. A Holocaust survivors' organization described the sale as "a cynical act of exploitation aimed at profiting from the writings of one of the most heinous Nazi criminals".[118] Rabbi Marvin Hier of the Simon Wiesenthal Center was glad to see the diary fall into Jewish hands. "At a time when Ahmadinejad's Iran regularly denies the Holocaust and anti-Semitism and hatred of Jews is back in vogue, this acquisition is especially significant", he said.[119] In 2011, a further 31 volumes of Mengele's diaries were sold—again amidst protests—by the same auction house to an undisclosed collector of World War II memorabilia for $245,000 USD.[120]
Mengele joined the Nazi Party in 1937 and the Schutzstaffel (SS; protection squadron) in 1938. He received basic training in 1938 with the Gebirgsjäger (light infantry mountain troop) and was called up for service in the Wehrmacht (Nazi armed forces) in June 1940, some months after the outbreak of World War II. He soon volunteered for medical service in the Waffen-SS, the combat arm of the SS, where he served with the rank of SS-Untersturmführer (second lieutenant) in a medical reserve battalion until November 1940. He was next assigned to the SS-Rasse- und Siedlungshauptamt (SS Race and Settlement Main Office) in Poznań, evaluating candidates for Germanization.[18][19]