I read around 250k collaborated with the Nazi's during the occupation of Ukraine, which was vital to stop the Russians starving them out(I've seen quotes from Hitler about that).
What you don't often hear about, is between
4.5 million and
7million joined the Red Army to fight the Nazi's instead. That's despite
Holodomor, being fresh enough in people's memories, where the soviets were seen to have exterminated millions of Ukrainians by the way of starvation.
Up to 200k joined the Ukrainian Insurgent Army(the UPA), who were no better than the Nazi's, from what I've learned. They fought with and against the Nazi's at points, against the Red Army(often fellow Ukrainians) and the Poles(military and civilians, often with any Jews they had rescued). There was also ethnic cleansing of the Poles in Volhynia during 1943, marching village to village, killing any Polish civilians they found.
All the above is probably why Ukraine had the among the highest
amount of military casualties in WW2, where 1.6m died fighting. Add up the same for the UK and the USA put together and then times it by 2 and it's still not quite as many as the Ukraine lost.
There was also huge amount of Ukrainian civilians who died too. 3.7m died from military activities or war crimes and 1.5m died due to war related famine or disease.
Ukraine as a nation were also responsible for the 4th highest numbers of rescued Jews according to the
Righteous Among Nations awards.
Complicated is the right word.