How does the world confront a Russian leader who is acting like Hitler?

How should the United Nations deal with Russia, which has a veto in the Security Council but is led by a war criminal?

After his massive attack on a sovereign Ukraine, Vladimir Putin cannot be treated as a normal leader. He must be branded an international pariah and condemned by the vast majority of nations as an outlaw.

The U.N. General Assembly should suspend Russia from participation at the United Nations, as it did to apartheid South Africa in 1974.

Some may scoff that this would be irrelevant since it won’t save Ukrainians in the short term. Neither will harsh economic sanctions that will only play out over time. And it’s too late to send more defensive weapons to Kyiv for Ukrainian troops.

» READ MORE: Why Putin's aggression will change the world | Trudy Rubin

Yet Putin clearly cares about his international image. Otherwise he wouldn’t be so obsessed about justifying his invasion by promoting the foul narrative that Ukraine’s leaders are a bunch of Nazis threatening Moscow and bent on “genocide” against Russian-speaking Ukrainians.

Maybe, locked in his COVID bunker, Putin really believes this nonsense. But the rest of the world has to demonstrate that it rejects his lies. As Ukrainian President Volodymyr Zelensky, who is Jewish, plaintively asked, in a speech to the Russian people on the eve of the invasion, “How could I be a Nazi?” (Note: The prime minister of Ukraine is Jewish, as well.)

In reality, Putin is aping Adolf Hitler, claiming the neighboring state of Ukraine has no right to exist, because he wants to annex it to Russia. The Russian leader has also promised to carry out “denazification” in Ukraine, which means Russian forces will seek to kill or imprison Zelensky and a list of other government leaders, along with civilians who oppose the invasion.

Since hundreds of thousands of Ukrainians are likely to demonstrate against any puppet leader imposed by Moscow, this opens the door for massive civilian casualties — and no one doubts Putin would be ready to inflict them. The Russian leader is already guilty of massive war crimes in Syria, where Russian planes deliberately bombed schools, hospitals, and markets in order to save the regime of Bashar al-Assad.

So it is critically important for the U.N. General Assembly to demonstrate that a majority of members — not just the West — sees through Putin’s lies. As Ukraine’s ambassador to the United Nations, Sergiy Kyslytsya, said Thursday: “Pretending now that the U.N. can work as if nothing happens will be immoral.”

That immorality was on full view at a meeting of the U.N. Security Council on Wednesday night, as Putin — speaking in Moscow — thumbed his nose at the world body, formally announcing the invasion was on, just as council members were discussing how to prevent it.

Ironically, the meeting was being chaired by Russia’s U.N. ambassador, Vassily Nebenzia, since Russia holds the rotating presidency of the Security Council at the moment. It was as if Saddam Hussein were chairing a council meeting discussing how to reverse the invasion and annexation of Kuwait.

To add insult to injury, Nebenzia claimed: “We are being aggressive not to the Ukrainian people, but to the junta that is in power in Kyiv.” You can’t get more cynical than that Kremlin doublespeak.

Translated: A Russian dictator has the right to remove a president chosen by a free vote of the Ukrainian public — and replace him with a Kremlin-controlled regime. And he can kill as many civilians as he needs to get the deed done.

If the United Nations lets Putin get away with this claim, then the world body might as well declare itself dead.

However, there are signs that a broad segment of the U.N.’s member states understands that Putin must not be allowed to get away with murder.

» READ MORE: Biden must hit Ukraine harder with sanctions | Trudy Rubin

The Kenyan ambassador to the Security Council, Martin Kimani, was quite blunt in a Security Council speech challenging Putin’s dream of restoring the Russian empire. If that were acceptable behavior, Kimani said, then every African country would be at war with its neighbors trying to change borders drawn by former colonial powers.

And other members have surely noted that Putin hinted he was willing to use nuclear weapons against any nation that tries to “interfere” with his invasion, saying this “will lead to the kind of consequences you have never experienced in your entire history.” Those are the words of a leader who could embroil the world in a nuclear war.

So it is time for the introduction of a U.N. General Assembly resolution to suspend Russia until such time as Putin pulls back from Ukraine. Or maybe indefinitely.

If enough U.N. members sign on, even China might recognize that its Russian ally is stabbing it in the back — by undercutting Beijing’s sacred mantra that no country has the right to interfere in another country’s sovereign affairs.

To paraphrase Ukraine’s Ambassador Kyslytsya on Wednesday: “There should be no purgatory for war criminals. They should go straight to hell.”

Meanwhile, the U.N.’s future is on the line, as is Ukraine’s — and perhaps the world’s.