Billed as the top star of the annual UN General Assembly debate, President Zelensky delivered the goods Tuesday, with the symbol of Ukraine’s war against an invader proposing novel ideas for global cooperation. 

Sporting a polo-style long sleeve shirt in his now-familiar olive hue, Mr. Zelensky addressed a receptive hall at Turtle Bay, even as Russia’s seat was empty except for Moscow’s lone deputy UN ambassador, Dmitry Polyanskiy, who at times was caught by the local camera making dismissive gestures.

Yet, the invader country seems more isolated than ever, as Mr. Zelensky contended that the Kremlin threatens the entire global architecture. “For the first time in modern history, we have a real chance to end the aggression on the terms of the nation which was attacked,” Mr. Zelensky said, noting that at least 140 countries have fully or partially endorsed Kyiv’s plan to end the war. 

That plan entails, among other provisions, a return of all territory Russia has usurped since its 2014 occupation of Crimea, including areas it has taken over since the February 2022 invasion. The invasion’s goal, Mr. Zelensky said, “is to turn our lands, our people, our lives, our resources into a weapon against you, against the international rules. Rules-based order.”

The 1994 Budapest memorandum dictated that former Soviet Republics rid themselves of nuclear weapons. “Ukraine gave up its third-largest nuclear arsenal,” Mr. Zelensky said. “The world then decided Russia should become a keeper of such power. Yet history shows it was Russia who deserved nuclear disarmament the most.”

As treaties and agreements deal with nuclear weapons, he said, Russia is “weaponizing” nuclear power, as in its occupation at Ukraine’s Zaporizhia, the largest nuclear plant in Europe. Here’s a “scary question,” he said: “The global security architecture offers no response or protection against such a treacherous radiation threat and there is no accountability for radiation black mailers.”

Even the theme on which almost every speaker at the assembly touched, climate change, was brought up by Mr. Zelensky — with a twist. “Thank God people have not yet learned to use climate as a weapon,” he told the assembly. “Some evil state” could utilize such a weapon with much more deadly results than the other effects of climate change around the globe. 

Another Russian weapon he highlighted is the blockade on Ukraine’s grain exports. In that context, he sniped at Hungary, Poland, and the Czech Republic, which are declining to import Ukrainian grains even as they allow deliveries through their territories. Yet, the speech was mostly aimed at the Kremlin.     

“While Russia is pushing the world to the final war, Ukraine is doing everything to ensure that after Russia’s aggression no one in the world will dare to attack any nation,” he said in concluding his speech. “War crimes must be punished, deported people must come back home, and the occupier must return to their own land. We must be united to make it and we’ll do it. Slava Ukraine.”

By internationalizing his country’s plight and turning it into everybody’s problem, Mr. Zelensky made a compelling case for world support of his war of liberation. Following his speech, Mr. Zelensky went for a first meeting with Prime Minister Netanyahu of Israel, a country that Ukraine had complained does not support it enough.

On Wednesday, the Ukrainian war leader will address the Security Council with a similar plea, and then will fly to Washington with President Biden on Air Force One. It is there that his call to arms is currently most needed.