No, not all German soldiers in World War II were Nazis, although the majority of them were members of the Nazi state. It's important to distinguish between the **German military** (the **Wehrmacht**) and the **Nazi Party** (the **NSDAP**), which was the political entity that ruled Germany under Adolf Hitler. While the two were closely aligned, membership in the Nazi Party was not a requirement for service in the military.
The **Wehrmacht** was the regular German military, consisting of the army (**Heer**), the navy (**Kriegsmarine**), and the air force (**Luftwaffe**). Soldiers in the Wehrmacht were expected to swear an oath of loyalty to Adolf Hitler, but not all of them were necessarily ardent supporters of Nazi ideology. Many joined out of a sense of duty, national pride, or due to coercion, especially as the war progressed and the German state became more totalitarian. Some soldiers were simply doing their job as part of a conscripted force, and not all were ideologically motivated to fight for Nazi goals.
However, the **SS (Schutzstaffel)**, which was Hitler's personal paramilitary force, was made up of fervent Nazis, and its members were committed to the Nazi ideology. The SS played a key role in enforcing Nazi policies, including the Holocaust and other war crimes. Members of the SS were often directly involved in atrocities, and their loyalty to Hitler and Nazi ideology was absolute.
While there were certainly soldiers in the Wehrmacht who supported the Nazi regime, others were less enthusiastic or even opposed to it. Some Wehrmacht soldiers were disillusioned by the war and the brutality of the Nazis, but many lacked the power to resist or speak out. In the postwar era, some Wehrmacht veterans distanced themselves from Nazi ideology, though their involvement in war crimes, particularly in Eastern Europe, remains a contentious topic.
In summary, while the majority of German soldiers during WWII were under the control of the Nazi regime, not all were Nazis in terms of personal belief or ideology. Many were simply soldiers fulfilling their military obligations during a time of war.