The United States and Israel officially quit the U.N.’s educational, scientific and cultural agency at the stroke of midnight, the culmination of a process triggered more than a year ago amid concerns that the organization fosters anti-Israel bias. The withdrawal is mainly procedural yet serves a new blow to UNESCO, co-founded by the U.S. after World War II to foster peace. The Trump administration filed its notice to withdraw in October 2017 and Israeli Prime Minister Benjamin Netanyahu followed suit. The Paris-based organization has been denounced by its critics as a crucible for anti-Israel bias: blasted for criticizing Israel’s occupation...