Billionaire investor Bill Ackman says Russia's attack on Ukraine means World War III has 'likely already started'

• Bill Ackman said World War III may have started and the US had been "slow to realize it."
• The billionaire said the US needed to impose harsher sanctions and stop buying Russian oil.

Bill Ackman said on Twitter that World War III may have already begun.

"WWIII has likely started, but we have been slow to recognize it," the billionaire hedge-fund manager said in a tweet thread on Saturday.

"We are in the early innings of Putin's global aspirations. With each 'victory,' he is emboldened to take more. He is testing us, and we are failing the test each time," he added, referring to Russian President Vladimir Putin.

Ackman said he had been having nightmares about the possibility of another world war. He compared the dreams to ones he had in 2020 before COVID-19 shut down the US. At the time, only a few thousand people had tested positive for the coronavirus in the US, but Ackman had said "hell is coming" and called for a nationwide lockdown during an interview with CNBC.

"In January 2020, I had nightmares about the potential for a pandemic, but everyone seemed to think I was crazy," Ackman said on Twitter. "I am having similar nightmares now."

Ackman said NATO and the US were acting out of "fear of provoking Putin," while Putin has said the West's support for Ukraine in the form of sanctions and supplies is "akin to declaring war."

Ackman, the CEO of Pershing Square Capital, added that there was more to be done before the US would enter "a hot war with Russia." The billionaire said the US should stop buying Russian oil and work to supply Ukraine with more weapons and intelligence. He added that if the sanction fail, NATO should reconsider enforcing a no-fly zone over Ukraine.

"When I was a child and learned about the Holocaust, I asked my grandparents why they didn't do more to save millions of people from genocide during WWII," Ackman said. " They didn't have very good answers. What will we say to our grandchildren when they ask us why we allowed tens or hundreds of thousands, or millions of Ukrainians to die?"

The billionaire's latest tweet thread came a week after he called for President Joe Biden to "set a real red line" and consider military intervention in Ukraine.

On Monday, Ukrainian President Volodymyr Zelenskyy called once again for an international boycott of Russian oil, as well as for the West to implement new and harsher sanctions.

Biden has called on Congress to approve $10 billion in aid for Ukraine. The proposal includes assistance to help bolster Ukraine's defenses and protect its electrical grid from disruption.

Biden has said US troops "will not be engaged in the conflict" and denied Ukraine's request for a no-fly zone. But he has said the US will act if Russia moves against NATO territory using the "full force of our collective power."

Ultimately, Ackman said China held the most power when it came to ending Russia's attack on Ukraine.

"Putin respects and likely fears China," Ackman said on Twitter. "China can elevate itself on the world stage by helping to resolve this crisis. Time is running short before many more 18-month-old children die."

China has yet to impose any sanctions on Russia, though Chinese Foreign Minister Wang Yi said on Monday the country was willing to act as a mediator between the two countries.

A spokesperson for Ackman said the billionaire had nothing more to add to his comments on Twitter.