Israeli tanks moved into the occupied West Bank on Sunday for the first time in decades in what Palestinian authorities called a “dangerous escalation,” after the defense minister said troops will remain in parts of the territory for a year and tens of thousands of Palestinians who have fled cannot return.

During that war, 700,000 Palestinians fled or were forced from their homes in what is now Israel. That Nakba, or “catastrophe,” as Palestinians call it, gave rise to the crowded West Bank towns now under assault and still known as refugee camps.