Einstein first came to worldwide public attention when he was one of the few German academics to openly speak against the First World War. The 1915 Manifesto he and three other academics at the University of Berlin signed was decidedly at odds with the current policies of the German government and the larger German academic profession, most of whom vigorously supported the war. Einstein's continued commitment to pacifism and outspoken support for internationalism made him an ideological foe for many German nationalists. His Jewishness and support for a Jewish homeland made him doubly distasteful for the Third Reich. As an emigre in the US, he critiqued the Nazis and refused invitations after the war to accept honors from German institutions.

It should be noted that Einstein's pacifism and internationalism were not unique; there were many Germans that were sympathetic or in agreement with this great thinker. While some German governments and ideologues castigated Einstein as a traitor, it is important to understand that not every German would have perceived Einstein as a traitor.