Who was the leader of Germany during the invasion of the USSR?

The correct choice is Hitler because he was the Führer of Nazi Germany during World War II and the primary architect behind the strategic decisions of the German military, including the invasion of the Soviet Union, known as Operation Barbarossa, which commenced in June 1941. Hitler's ideology and leadership played a pivotal role in the aggressive military strategies employed during the war, and his direct involvement in planning and executing the invasion reflects his significant authority in the German government.

Other figures like Goebbels, Rommel, and Himmler held important roles within the Nazi regime, but they did not possess the same level of control over military operations or strategic planning. Goebbels was the Minister of Propaganda, Rommel was a notable field marshal but not a decision-maker at the highest levels, and Himmler was the head of the SS and focused more on internal security and the Holocaust than on military strategy. Thus, Hitler's leadership is the critical factor in understanding the German invasion of the USSR.