President Biden’s ambassador at the United Nations, in a startling development, is siding with Russia against Ukraine’s challenge to Russia’s standing as a permanent member of the Security Council capable of vetoing its resolutions.

In an interview with CNN this morning, the American envoy, Linda Thomas Greenfield, was asked about a demand made earlier this week by her Ukrainian colleague, Sergiy Kyslytsya, to strip away Russia’s permanent membership in the 15-member council. 

“Russia is a member of the Security Council,” Ms. Thomas Greenfield said. “That’s in the UN Charter.”

The Ukrainians are arguing that, in actuality, the United Nations Charter — the foundational treaty of the world body — does not list Russia as a member of either the Security Council or any other part of the UN. The membership of the Security Council is listed in the treaty’s article 23. It says: 

“The Security Council shall consist of fifteen Members of the United Nations. The Republic of China, France, the Union of Soviet Socialist Republics, the United Kingdom of Great Britain and Northern Ireland, and the United States of America shall be permanent members of the Security Council.”

No resolution to change that was passed in 1991, when the USSR collapsed and Russia, in a letter to the UN secretary general, claimed the USSR’s security council seat, which is precisely the point Ukraine is making.

Ambassador Thomas Greenfield, in her interview with CNN, insisted, “we are going to hold Russia accountable for disrespecting the UN Charter. And they have been isolated in many different ways.” Her blunder on what the charter says, though, is viewed by Ukraine as not only inaccurate but as making it harder, even impossible, to hold Russia accountable within the United Nations system.

The Union of Soviet Socialist Republics was a confederation of 15 countries. During its existence only Ukraine and Belarus voted independently of the Soviet Union. USSR members that are now independent countries — including the Baltic states that are now members of NATO — might have as much of a claim as Russia to the USSR’s permanent seat. 

Ambassador Thomas Greenfield’s error as to what the charter says stands in sharp contrast to the written record pointed out by Ambassador Kyslytsya. He pointed out the language of the charter in an open meeting of the Security Council Thursday, when Ms. Thomas Greenfield was present. 

America’s resistance to that interpretation of the charter is especially curious as countries around the globe — inspired by the bravery of the Ukrainian people and their president, Volodymyr Zelensky — play catch-up in the effort to increase diplomatic and economic pressure on Russia. 

The Security Council is due to gather this afternoon to take to the General Assembly an American resolution that Russia vetoed late last week. In the Assembly, which includes all 193 UN members, no country has a veto power. None of its resolutions, however, can be enforced. Unlike Security Council resolutions, Assembly votes are mostly toothless declarations. 

Ms. Thomas Greenfield said that just because Russia is a Security Council permanent member “does not mean they’re protected from criticism, protected from isolation, and protected from condemnation.”

As yet the Kremlin’s strong man, Vladimir Putin, seems unimpressed. Nor can Russia be fully isolated if Ukraine’s stance on Article 23 is rejected. In the Council’s vote last week, three powerful countries — Communist China, India, and the United Arab Emirates — abstained on the American resolution that deplored Moscow and demanded it take troops out of Ukraine.