Why does Israel not allow the original residents of Israel who fled during the 1948 war to return to their homes ?
The main bulk of Palestinian refugees were created through the ethnic cleansing of Palestine at the hand of Zionist militias between 1947-1948 and the subsequent establishment of the state of Israel. This campaign of ethnic cleansing took place before and during the war of 1948, and saw approximately 800,000 Palestinians expelled from their homes, and over 530 villages being demolished. Another large wave of displacement and expulsions followed the war of 1967. Israel depends upon the displacement of these refugees and their descendants to maintain itself as an ethnocracy.
Israel prevents Palestinian refugees from returning because it claims they are a security threat. However, seeing as Israel is a settler colony built on stolen land, it did not have the population numbers to sustain itself. It could only be established by creating new demographic realities on the ground, these new realities necessitated that approximately 80% of the Palestinians in what is today considered Israel be ethnically cleansed to maintain a demographically stable Zionist ethnocracy. In short, Israel can only exist because millions of Palestinians are scattered refugees all over the world, simply because they are not Jewish.