From a piece in the Grayzone:

"They would become an official part of Ukraine government too. Sakwa says that several core ministerial positions in the Ukrainian coup government were taken by the Right Sector and Svoboda, both openly neo-Nazi parties, including top national security, defense and legal posts. The deputy prime minister and the minister of justice were both members of Svoboda. Andriy Parubiy, one of the founders of Svoboda with what Sakwa calls “a long history of ultra-nationalist activism” became secretary of the National Security Defense Council. Sakwa calls Parubiy’s appointment “astonishing.”Stephen Cohen, who was Professor Emeritus of Russian studies and politics at Princeton, in an article on Ukraine called “America’s Collusion With Neo-Nazis,” says that the coup government in Ukraine has systematically rehabilitated and memorialized Ukrainian Nazi Germany collaborators. Among the Nazi collaborators memorialized by the government of Ukraine is Stepan Bandera who allied with the Nazis and committed atrocities against Jews, Poles and Russians. Sakwa reports that “a giant portrait of Bandera was . . . on the stage during the Maidan protests.”

https://thegrayzone.com/2022/03/31/partnering-neo-nazis-ukraine-history/

That, along with groups such as the Azov battalion and other paramilitary groups being included into the Ukrainian national guard, have been the key influence of the Nazi elements.

I don't know how long the soviets would have been able to fight without the US, and I don't know enough about the split of Poland to comment, and either of those facts do not diminish the sacrifice Russians made to defeat Nazi Germany.