UNITED NATIONS—The Obama administration broke from a longstanding tradition of U.S. defense of Israel at the U.N. and allowed the passage of a resolution harshly criticizing the country’s expansion of Jewish settlements in the Palestinian territories.

It was the first time in 36 years the Security Council was able to adopt a resolution addressing the issue of Israeli settlement construction, an outcome made possible by the abstention of the U.S., which had veto power.

Throughout...