The Armed Forces of Ukraine allowed a 30,000-strong group of Russian troops to quietly withdraw from Kherson in the fall of 2022 due to pressure from the United States on Kyiv.
Source. This is reported by The Washington Post journalist Bob Woodward in his book "War" after conversations with U.S. officials.
Specifically, according to the journalist's information, when the Ukrainian army was liberating Kherson, American intelligence warned that there was a risk of a nuclear strike if the Russians lost significant forces during their retreat from the city.
The plan for the Armed Forces of Ukraine was to pursue the retreating Russians and carry out massive attacks, but this did not happen – the Russians retreated without significant losses.
Before the Russians' exit, American intelligence warned Biden that an attack by the Russian armed forces could lead to a 50% chance of a nuclear strike from Putin.
U.S. officials held a phone call with the Russian Chief of Staff Gerasimov, who confirmed that in the event of significant losses during the retreat from Kherson, the Russians would use nuclear weapons.
After this, the Russians received a sort of security guarantee and peacefully crossed to the left bank, taking all their equipment and 30,000 personnel, Woodward writes.
The author of the book "War" claims that the fear of Americans regarding nuclear weapons forced the Ukrainian armed forces to simply wait, allowing Russia to preserve its forces, regroup, and capture significant territories of Ukraine.
Ukrainian journalist Andriy Tsapliyenko wrote in his Telegram channel: "I received an important document from (Ukrainian) intelligence. It was a detailed schedule for the withdrawal of the Russian group, which was planned in several stages from October 21 to November 7. There was also a schedule for the transportation of over 6,000 units of weapons, military, and special equipment. And I then had a question – if we know where they are, why aren’t we striking? Finally, everything fell into place."
Background. Recall that the Washington Post reported how Sullivan persuaded India and China in 2022 to "save the world" from Russian nuclear threats. Sullivan's strategy contained a paradox: Washington wanted Russia to be defeated by Ukraine's hands, but not in a way that would provoke a nuclear conflict.