That's one view... as i understand it, the land was bought and paid for from its justifiable owners. Include the fact that Jews have been present - although not always in political control of - that land for more than 3200 years, i think it makes a strong case for israel. Also throw in the religious demand of muslims to destroy the jews, as well as not only the sanction of, but the glorification of the use of deceit and violence to attain its goals, i find it very difficult to have any trust in the muslim case against israel.
If the jewish people have one land to call home in all the world, that land is israel, and has been for millennia. Palestinians and other involved arabic countries have continually refused to accept any kind of compromise that would legitimize Israel in any way. Prior to the formation of Israel, the land which is now israel as well as the palestinian territories were part of the ottoman empire, captured by the british.
The furthest i can concede at this time without further knowledge is that indeed the British Empire was given control of the areas of the Ottoman Empire by the League of Nations after WWI. Promises were made to both sides, but not for ALL of the land - each side would get some of the land - even if there was a misunderstanding by either or both sides that they would get ALL of the land. The british eventually turned it over to the UN after WWII, and after failing to find a solution that would satisfy both sides. The UN offered a two state solution, which the arabs refused. The Jews accepted, and the arabs attacked, and have continued to do so ever since.