I think this interview goes a long way to shedding light on von Trier and his comments, especially related to (a) how he actually thought he was half-Jewish for a large chunk of his life, and (b) the historical tension Danes have had with Germans for generations. Poor judgment, poor follow-up, and a lot of knee-jerking, but nothing that doesn’t make sense once the smoke clears and emotions simmer.
Dunst, btw, won Best Actress at Cannes for von Trier’s film.