https://www.dw.com/en/germany-criminalizes-denying-war-crimes-genocide/a-63834791?maca=en-newsletter_en_bulletin-2097-xml-newsletter&r=57279351345253404&lid=2353404&pm_ln=177220   

Neither Deutsche Welle nor the German government reveals who it is who gets to determine the unchallengeable war crimes.

Germany gave in to the Jewish lobbies and long ago criminalized "Holocaust denial."  I have wondered why.  If the Holocaust is true, it can stand on the facts and remain undamaged by unsupported denials.  What the criminalization of inquiry and debate does is to prevent us from knowing the true dimension and history of the Holocaust. My understanding from reading is that Austria, some other European countries and Canada do not permit any examination of the Holocaust. We are simply told that it is true, but it can't be examined, and that is the end of it.

The Germans have suffered substantially from declared and unexamined "truths."  In World War I Germany was accused of its soldiers bayoneting  Belgian babies. (In the 21st century a version of this falsehood was repeated against Iraqi troops in Kuwait.) The propaganda created enormous hatred for Germany.  These decades later after the normalization of mothers bayoneting their own babies, it might not have the same effect.  But what if it had been legislated a criminal act to investigate whether German soldiers murdered Belgian babies?  The propaganda would rule.