I have criticized the president’s treatment of Israel since the early days after Oct. 7, when most Israelis were singing his praises. But Mr. Biden’s greatest error in this war lies elsewhere, in his betrayal of Gazan civilians and cruel disregard for their humanity. This set in motion a cascade of problems that have bedeviled the war ever since.

When you hear that Gazans are “trapped,” you are encountering a Biden policy choice. It didn’t have to be this way. Gaza’s Rafah borders Egypt, a U.S. ally that relies on $1.3 billion in U.S. aid a year. In contravention of international law, Egypt has sealed its border to Gazan refugees next door. Mr. Biden hasn’t lifted a finger to stop it.

On the contrary, the administration embraced Egypt’s position early on and demanded that Israel not “displace” civilians into Egypt. “No forcible displacement” became Secretary of State Antony Blinken’s absurd mantra as Gazans were massing at the border and begging to be allowed out.

Along with the United Nations and the NGO complex, Mr. Biden provided Egypt cover as it denied Gazans their human right to flee war. As the Journal’s editorial board noted, “Only when it can damage Israel does it become the liberal position to close the borders and keep refugees penned in a war zone.”