In places like Czechia, Slovenia, Croatia, Serbia, Bosnia, Montenegro, Albania, and Greece (as you can see, these are mostly in SE Europe), the main theme of WW 2 was civil war virtually from the time of Nazi occupation until the end of the war.
You can argue that something similar happened in France.
In Ukraine and Belarus, the main theme once again was civil war.
So it looks like racist fascism or Nazism had a lot of trouble in the USSR, SE Europe, and the southwest of the Austro-Hungarian Empire.
The USSR had many Jews and the country had treated them very well. The new nation waged war on antisemitism and many of the workers and peasants were cured of the disorder. Many Jews were good Communists who worked for the people.
In Slovenia and Czechia, the Nazis engaged in a lot of ethnic cleansing and moving populations around based on racial classifications and that did not go over well. The Czechs were seen as Slavs are were supposed to be dealt with per Generalplan Ost.
Probably the same with Slovenians, except for some who were seen as Germanized. But they split the Slovenian population racially, cleansed some people to make way for a subgroup of Germans, and split the country with Italy, who also cleansed a lot of Slovenians from their end. Bottom line is Slovenians started rebelling pretty quickly.
In SE Europe, the Jews of Albania, Greece, Croatia, Serbia, Montenegro, Macedonia, and Bulgaria were Sephardic Jews. The Sephardics had long been very well integrated with their local cultures, hence antisemitism levels were low in these places since the Middle Ages. There were also Sephardics in Spain, Portugal, Italy, Turkey, the Caucasus, etc.
Some include North Africa among Sephardics, but it is better to see them as Mizrachis or better yet Maghrebi Jews.
The Jews of the Arab World are also called Sephardics sometimes, but they are better seen as Mizrachis.
There is probably not a good word for the Jews of the East in places like India, China, and Uzbekistan.
It is true that in terms of rites, all of the Jews of those places tended to use Sephardic as opposed to Ashkenazi rites.
Basically, Sephardics came from Spain and Portugal. and with the Reconquista, many were thrown out of Spain and headed to the countries in Southern and SE Europe that I described earlier. However, this exodus has been much overblown by hysterical Jews and their allies. Maybe 2