There is a good article in The Spiegel about the help the German Nazi’s got from all over Europe.
I noticed that the Croats and Slovaks came in for criticism:
Germany’s troops didn’t have the whole of continental Europe under the gun to the same extent. Outside the Third Reich and the occupied territories the Germans needed the help of foreign governments in their monstrous murder project — in the west as well as the south and southeast of Europe. Their support was strongest among the Slovaks and Croats whom Hitler had given their own states. The Croatian Ustasha fascists set up their own concentration camps where Jews were killed “through typhoid, hunger, shooting, torture, drowning, stabbing and hammer blows to the head,” says historian Hilberg. The majority of Croatian Jews were killed by Croats.
What this article does not mention, and what most people do not know, is that according to the United States Holocaust Museum, “The Croat authorities murdered between 330,000 and 390,000 ethnic Serb residents of Croatia and Bosnia during the period of Ustaša rule; more than 30,000 Croatian Jews were killed either in Croatia or at Auschwitz-Birkenau.”
Anyone trying to understand what happened to Yugoslavia needs to know this.
The Dark Continent: Hitler’s European Holocaust Helpers – SPIEGEL ONLINE