What is the theme in Waiting for Anya by Michael Morpurgo?

War atrocities are a major theme in the book. During World War II, the Germans had the idea that Jews were criminals who weakened the government and the pure Aryan bloodlines of true Germans. For this reason, the Germans rounded up all the Jews in their own country and the countries they invaded during the war and placed them in camps where they would be put to death or worked to death.