Understandably so. Thus it will be incumbent on the "world community" to either find a place(s) nobody else owns or wants or to purchase such a place and move the Palestinians to their new digs. Denmark might be prevailed upon to sell Greenland, e.g. Or the USA might be willing to donate Shemya to the cause...
The borders were set up long along. I believe mainly by the British.
And the borders were authorized an approved by the UN. Importantly, Jewish settlers actually owned virtually every square inch of what is now Israel, having bought the land from the Arab landholders.
I believe incorporating land by conquest is now verboten by international law.
If there is such a law, it is unenforced. Moreover, the Israelis conquered the West Bank in 1967 -- when I'm virtually certain such a law did not apply.
More importantly, Israel WAS ATTACKED, beginning the war. By all rights, the arabs forfeited their rights to the land when they began the war.
Mark