For many centuries there was a Jewish presence in Palestine and in many other Arab nations. Islam recognizes Jews as the people of the book (bible) and they have always had a certain status and respect for this reason.
The tolerance of Muslims was never perfect -- but it was a lot more enlightened than in the Christian world.
In many Arab nations the Jews spoke Arabic in preference to Hebrew -- and these Jews were also assimilated culturally to some extent. They were generally prosperous and content. There were no pogroms in the Arab world to match what happened in Russia, for example, under the Czars.
Enter Zionism and the whole equation changed.
If it is true that the Zionists in Germany made a deal with Britain during WW I -- at a point when Germany had all but won the war -- to turn the tide by bringing America in on the side of Britain in return for Palestine -- this would explain a great many things that have happened since.
It would explain the Balfour Declaration -- Britain's promise during WW I to create a Jewish settler colony in Palestine -- and it would explain the hostility of the German people to the Jews. Of this happened, then obviously the Germans felt betrayed. It would also explain why Britain reneged on its promise to -- I think it was King Hussein of Saudi Arabia -- but correct me if the name is wrong -- to liberate the Arab naton after the war if they would help the Brits defeat Turkey in WW I. This was the famous successful desert campaign of Lawrence of Arabia. Later, Lawrence went to Versailles where the peace treaty was hammered out -- and was aghast at Britain's betrayal of his Arab friends. Lawrence later refused a commission in the British AF as a personal protest.
At the time of WW I there was very little overt anti Semitiism in Germany. Conditions in Germany were a world apart from the pale in Russia, where many Jews lived in impoverished ghettos. The Jews of Germany were relatively few in number -- but they were bankers, industrialists, scientists, doctors, professors etc
In short, they were a very powerful group -- with the clout to actually deliver on such a deal.
What is remarkable is that no scholar to my knowledge has investgated this whole scenario -- which was proposed not by me but by a Jewish financier, many years ago.
I will search for the link. MHG