Its not that simple because more than the land, the religion is the problem. Neighbouring countries have an issue with that, which goes far beyond a claim of land. Its less of an "We want that land so we can live there" and more of an "We want those jewish people out of here".

Israel even offered them land (as part of the two-state-solution which the Hammas stopped in the end) but that is not what they want.

Why do you think neighbouring countries, who themselves own land that was originally part of Palestine would attack Israel to claim land for.... what really? For Palestine? A country that doesnt even exist anymore?