The reason that the nazi regime ended up in their halls in the first place, was because bott, the USA and the Nazis had a common enemy. Communist USSR.
Enemy of my enemy is my friend.
Which is why the OSS, and later the CIA certainly do have a history of co-operating with the ultra far right all over Europe. The reason is simple. To fight against the left, largely represented by socialists and communists at that time.
Their fighting methods included false flags, mass shootings, bombings, sniping into protester crowds, kidnappings, torture. Methods straight out of the "How To Spread Freedom And Democracy" manual.
I recommend doing a bit of reading and watching on Operation Gladio. Do note, that despite the fact that US used these ultra-far-right forces to shape European politics, there weren't any countries where Nazis took over the government completely.
As for Ukraine, CIA had a whole separate operation dedicated to working with ethnic minorities of USSR. Check out the link to the document I posted in the first post of this thread. Or just google the title, which is Cold War Allies:The Origins of CIA's Relationship with Ukrainian Nationalists.
