Those historians who take an intentionalist line, like Andreas Hillgruber, argue that everything that happened after Operation Barbarossa was part of a masterplan he credited Hitler with developing in the 1920s.
The Canadian historian Erich Haberer has contended that the "Baltic flashpoint of genocide", as the killings committed by Einsatzgruppe A between July-October 1941 are known to historians, were the key development in the evolution of Nazi anti-Semitic policy that resulted in the Holocaust.