Oh Dear - I don't know where to start!
Trying to keep it short, I think it began when the Hebrews were dispersed from the Holy Land after Roman takeover after 70 ad. Some went north others went south.
Many years later, those who went north (Ashkenazim) began increasingly to be persecuted (why?).
Eventually, in the early19th century a movement was started, mostly among young Jews, determined to return to the land they thought of as their only real home.
At the same time there was the influx to the USA.
The 'homeland' wasn't called Israel or Palestine at that time. It was inhabited mainly by Arabs/Muslims, and a few Jews who had been there since the dispersal. That was the start of Zionism.
Those who had fled south (Sephardim) don't seem to have had so much persecution, and usually managed to live in peace with their Arab neighbours, and Muslims, after that religion developed around the 7th century.
It seems that the current troubles started in 1948 when the Holy Land became Israel. There was a terrible war between Jews and Arabs/Muslims.