Peres pushed for a location that had a building. Either he ignored the possible ownership of the land in question or he, like many in the government, didn't take the settler movement, Gush Emunim, seriously as a potential power.
None of the politicians of any party, even the Right, had a clue that within a few decades there would be hundreds of thousands of Jews in Judea/Samaria. And if the government would solve the legal issues and give building permits, there would be more than double the number.
This should not be in the hands of the Supreme Court. Prime Minister Netanyahu is wrong in leaving those Leftist ideology-driven judges to make law. The Government and Knesset are supposed to make the laws, not the Judicial branch.
In the half a century since the 1967 Six Days War we periodically hear politicians talking about annexing the Land we liberated in that war for survival, like Naftali Bennett right now. All international legal precedent is that a country that wins a war, especially a war for its very existence and survival, automatically annexes whatever land it finds in its possession. That's the way of the world.
And, yes, of course, Peres was part of the ruling team that decided Israel should do the very opposite. He and his ilk had this totally fokokt idea that the Arabs would be willing to live in peace in exchange for those "territories." This was a mistake, the infant of his "New Middle East" fantasy, which made him the darling of those trying to find a politically correct way of destroying the State of Israel.
Now, we are stuck with horrendous politicians running the country. Gd willing, someone will get the wisdom and guts to fix this mess.