It depends on what is meant by the term "Palestine".
If it is referring to the British Mandate of Palestine, this was important for Jews because it established that it was in the international interest (League of Nations) to create a "national home for the Jewish people". Nobody aside from Jews had really wanted that or wanted to implement that for nearly two thousand years.
If it is referring to the current Palestinian Authority, this was critical to Jews because it legitimized, to a certain extent, the Palestinian Arab struggle for identity and self-governance. Jews could no longer point to "amorphous Arabs" causing problems, but a specific and troubled population looking for a state of their own.
The Exile of Jews from palestine is known as the Diaspora
No. For most of the last 2,000 years, the Jews in Palestine were a repressed minority (or on occasion a repressed majority). Probably the most bloody period for Jews in Palestine was during the Crusades when Christian leaders slaughtered numerous Jews, especially in Jerusalem. However, Jews suffered other calamities in Palestine, such as the destruction of both Great Temples and the exile of significant portions of the Jewish population.
Because Palestine keeps attacking the Jews.
Israel was created for the Jews so they could have a homeland after the Holocaust. Palestine was under mandate by the British who encouraged the creation of the homeland to be carved out of Palestinian land. This area had been occupied by the Jews in ancient times.
no
There have always been Jews in Palestine. They were not the majority between the years 132 CE and 1949 CE.
No. Jews had already been migrating to Israel/Palestine in substantial numbers since 1919.
The declaration gave the Jews of Palestine the hope that they might one-day have a country of their own.
Diaspora.
they had part of palestine.
no
Sanhedrin