I have a question about the arab israeli conflict?

why do the israelis say that there was no state in palestine before they immigrated there?the israelis claim that there was some arabs there but they were under british rule and they had no state so this gives them the right to go over there and settle in the country right?i mean a lot of countries in the middle east were being occupied by britain and france at the time(like egypt,sudan,syria,lebanon..)but it was a known fact that there were people in these countries who will oneday rise up and expel the colonizers(and that`s what happened in the 50s and 60s)so why didn`t the israelis go to these countries and say (hey this is an empty land we will settle here)so WHY THE HELL did they go to palestine and occupied it although there were palestinians there who would have gained their independance as other middle eastern people if the israelis hadn`t come?