The majority of the population of Palestine had been Arabic since the seventh century A. so they are the people who have the right in Palestine. In short, Zionism was based on a wrong, colonialist world view that the rights of the original people of Palestine didn't matter. The Zionists wanted to establish a nation for the Jews in Palestine and this was the beginning of the problems in Palestine. .
The Arabs' opposition to Zionism wasn't based on anti-Semitism as some of the Jews say but it was on a reasonable fear of the Palestinians losing their homes and their country. .
The Zionist position is that they showed up in Palestine in the end of the 19th century to say false claims that they are the rightful owners of Palestine as their ancestors lived in this place so it is their homeland. .
Jews bought land and started building up the Jewish community in Palestine to make a beginning to increase their power in Palestine. They were met with violent opposition from the Palestinian Arabs, the Jews made false claims that this came from the Arabs' inherent anti-Semitism. The Zionists said during this period that they were forced to defend themselves against the attacks of the Arabs and, this same situation continues till now in Palestine.
The problem with this explanation is that it is simply not true. What really happened was that the Zionist movement, from the beginning, looked to a practically change the Arab population and bring in their place the Jewish settlers to make a home for them in Palestine. They had an objective that Israel could be a wholly Jewish state or as much as was possible. Land bought by the Jewish National Fund was held in the name of the Jewish people and could never be sold or even leased back to Arabs.
The Arab community, became aware of the Zionists' intentions, strongly opposed further Jewish immigration and land buying because it was a real and strong danger to the existence of Arab society in Palestine.