Yad Vashem Chief Historian Professor Dina Porat:
It is a well-documented and undisputable fact that many years before his rise to power, Adolf Hitler was already obsessed by the notion that the Jews constituted an existential danger to the humankind, and thus world Jewry needed to be eliminated at all costs.
This ideology began to be formed by Hilter when he was a solider during World War I. Hitler believed that the war had not only been caused by the Jews, but also that the Jews had stabbed Germany in the back. Hitler went on to develop his obsession with the Jewish problem in his infamous manifest, Mein Kampf, and later in other central documents of the Nazi Party that began to establish itself in the 1920s. Finally, in a speech at the Reichstag on January 30, 1939, Hitler stated outright that if world Jewry would ‘once again drag the entire world into a World War’ then the only possible outcome would be the extermination of the Jewish people.
All of these facts clearly show that Adolf Hitler was determined to annihilate the Jews, and subsequent historical events demonstrate how this mania developed them into official Nazi policies. Hitler didn't need anyone else, including the Grand Mufti of Jerusalem, Haj Amin al-Husseni, to come up with the idea to implement the "Final Solution."
The Grand Mufti's visit, over two years after the outbreak of WWII, came once many "Final Solution policies were already in full swing. Almost immediately following the invasion of Poland in September 1939, Reinhard Heydrich received instructions from Berlin giving the orders to establish ghettos and Jewish Councils in the occupied Polish territories. It was widely understood amongst the SS that the ghettoization process of the Jews in Europe was a stepping stone for the implementation of the "Final Solution." In addition, after the invasion of the Soviet Union in June 1941 the SS Einsatzgruppen began the mass murders of the 1.5 million Jews in Lithuania, Russia, and the Ukraine. The first extermination camp, Chelmno, began operations at the beginning of December 1941 just days after the meeting with the Grand Mufti. The building of the death camp had already been underway for several months when these two leaders met.
Therefore, the way Prime Minister Netanyahu worded his comments was historically inaccurate from the perspective of the "Final Solution" of European Jewry, but was on point for plans to expand this policy to Jews living in Mandatory Palestine. The Mufti had a specific agenda in meeting Hitler in 1941. The Protocol from this fateful meeting specifically states that "The Fuehrer replied that Germany stood for uncompromising war against the Jews and that naturally included active opposition to the Jewish national home in Palestine." Hitler promised that he would carry on the battle to the total destruction of the "Judeo-Communistic Empire" in Europe. The Mufti of Jerusalem was no lover of the Jewish people. He was an ardent antisemite, but the idea of the "Final Solution" was Hitler's alone, as was the implementation of its appalling policies and actions.