At the Guggenheim, trustees of the board were required to donate at least $100,000 a year, according to Thomas Krens, director emeritus at the Solomon R. Guggenheim Foundation, who said he had contact with Potanin for more than a decade. He recalled the Russian billionaire as steadily supporting exhibitions of Russian art and being “quiet, not outspoken” at meetings.

“Many oligarchs saw an opportunity and moved on that” to bolster their reputations with philanthropy in the West, Krens said in a telephone interview. “The response to this war and to Putin’s strategy has been one of trying to ostracize or shine a spotlight on the money and where it came from.”

Scant Sanctions
Many of the New York donors haven’t been sanctioned. That doesn’t prevent the questions.

Yancey Spruill, chief executive officer of New York-based DigitalOcean Holdings Inc., was asked at a conference last week about Len Blavatnik, a British-American billionaire whose Access Industries is the technology company’s largest investor.

“Educated in American universities, Columbia, Harvard Business School, made his money as an American,” Spruill said in response on March 8. “I know there’s a lot of speculation,” he said, adding that Blavatnik “has been knighted by the Queen of England.”

Blavatnik was born in Soviet Ukraine and grew his fortune in the Putin era when Russia’s state-owned Rosneft bought out his energy firm. At $36.9 billion, his net worth exceeds that of Potanin, according to the Bloomberg Billionaires Index.

“What is happening in Ukraine is unimaginable and we, along with all fellow Americans, hope and pray that the conflict ends quickly and that all Ukrainian citizens are once again able to live their lives in peace and freedom,” Access Industries said in a statement.

Blavatnik has donated across the political and philanthropic spectrum, including to the Central Park Conservancy, Carnegie Hall, the Mount Sinai Health System and New York Governor Kathy Hochul.

Tough Tracking
It’s hard to track the full extent of charitable giving as institutions often don’t disclose their donors out of concern they’ll receive backlash over the politics of benefactors, Szakonyi said. Disclosures of specific donations may be in broad ranges or as even vaguer minimum amounts, and in some cases there may be no values disclosed at all, he said.

And even though some institutions are asking billionaire donors to step off their boards, they aren’t returning funds or closing exhibits. For example, the Guggenheim still carries an ongoing exhibition by Moscow-born artist Wassily Kandinsky that was sponsored by benefactors including Potanin -- though his name has since been removed on the museum’s website.