We are all to blame for the war raging in Ukraine, according to that country’s ambassador to the United Nations, Sergiy Kyslytsya. One of the most interesting, thoughtful, and provocative diplomats to grace Turtle Bay in quite some time, the Kyiv-born diplomat believes everyone missed the cues that led up to Russia’s attempt to devour his country. 

He says it all started on Christmas Eve 1991, when Russia was allowed to inherit the Soviet Union’s seat at the UN, including on the Security Council, with no authorization from the member states. “Russia was against the principles of the United Nations from the very outset,” Mr. Kyslytsya says in his Midtown office. “We are all guilty of what is going on right now.”

A man with a serious streak that every once in a while is interrupted by a wicked quip that he delivers without even a smile, Mr. Kyslytsya is the consummate diplomat. Yet, unlike Dezi, the meek black-and-white office dog who greets guests with a happy tail-wag instead of a bark, the ambassador has rhetorical teeth that at times are decisively undiplomatic. 

War criminals don’t go to purgatory; they go straight to hell, he told his Russian counterpart, Vasily Nebenzya, during a Security Council session shortly after Russia invaded Ukraine in 2022. At another time, he told the UN General Assembly that President Putin doesn’t need a nuclear weapon to kill himself, like “the guy in Berlin did in the bunker.”

The issues with Russia started before its forcible annexation of Crimea in 2014, the 2008 Georgia invasion, or the propping up of Syria’s president, Mr. Kyslytsya says. They started long before the current Ukraine war. “All of us allowed the Russian Federation to divert from the path of democracy,” he says. “We allowed Russia to do the nastiest things, and every time they would do something, they would all say, well, probably it’s the last time they would do it.”     

Following the collapse of the Soviet Union, Russia, “right in front of our eyes, turned from embryonic, nonexistent democracy to a dictatorship, and later to autocracy,” the ambassador says. At the same time, Western intelligence, especially in Washington and London, missed the resilience and maturity of Ukraine’s new democracy.

In 1994, America and the United Kingdom signed the Budapest Memorandum with the Russian Federation. In it, Kyiv was convinced to give up the nuclear arms that were deployed in Ukraine, in exchange for guarantees that its territorial integrity would remain intact. In retrospect, those who were responsible now regret it, admitting they misread realities on the ground. 

“I feel a personal stake because I got them to agree to give up their nuclear weapons,” President Clinton told Ireland’s RTE last month. “None of them believe that Russia would have pulled this stunt if Ukraine still had their weapons.”

A few years earlier, in 1991, the West was concerned about the emerging Russian Federation’s control over its nuclear arsenal, Mr. Kyslytsya says. Also, everyone remembered how, following the 1917 revolution, the Soviet Union nationalized all of tsarist Russia’s assets. After the fall of the USSR, debt owners, banks, businessmen, and others feared a similar loss. 

Utilizing such concerns, Moscow convinced everyone to transfer all Soviet belongings to the new, supposedly responsible Russian Federation. Among those assets was the USSR’s permanent seat on the UN Security Council. Yet, as new Russia came to be, on Christmas Eve 1991, it didn’t even have a UN ambassador. Moscow’s envoy at Turtle Bay, Yuli Vorontsov, was appointed in 1990 by the last Communist Party secretary general, Mikhail Gorbachev. 

The Russian Federation’s first president, Boris Yeltsin, did not appoint Vorontsov. Yet he gave him a letter that was delivered on December 24, 1991, to the UN secretary-general, Javier Perez de Cuellar. The writ declared that the seat that until then belonged to all 15 Soviet Republics — except Ukraine and Belarus, which had their own — would be transferred to the new country, Russia.

“Yeltsin’s letter was never formally discussed, neither by the Security Council, nor by the General Assembly,” Mr. Kyslytsya says. The Soviet Union held the rotating council’s presidency that December, and when council ambassadors returned from their holiday break, they saw in front of the USSR’s Vorontsov a new country nameplate.

“Under the Christmas tree, Moscow found a new nameplate,” Mr. Kyslytsya says, describing a circular procedure in which the Soviet diplomat, Vorontsov, delivered a letter to de Cuellar, who then sent it to the Security Council president, who just happened to be Vorontsov. The council never discussed, let alone approved, the transaction. 

The property currently housing the Russian embassy to the UN, on Manhattan’s East 67th Street, is registered in New York City to Ukraine and Belarus and Russia, Mr. Kyslytsya says. “Russia didn’t want to have its properties certified. They wanted to show up in every single bank around the world and say, this is a Soviet account, now it’s ours. This is a Soviet building, it’s ours. This is a Soviet fleet, it’s ours.”

In winter 2022 the West assumed that President Putin would just as easily gobble up Ukraine. Things changed once President Zelensky said he preferred arms to a ride out of the country. “I hope that now, when governments analyze situations, they would stop looking at our part of the world through Russian glasses,” Mr. Kyslytsya says.