[1] In 1925, Hertz became ordinarius professor and director of the Physics Institute of the Martin Luther University of Halle-Wittenberg.

Since Hertz was an officer during World War I, he was temporarily protected from National Socialist policies and the Law for the Restoration of the Professional Civil Service, but eventually the policies and laws became more stringent, and at the end of 1934, he was forced to resign his position at THB, as he was classified as a "second degree part-Jew" (his paternal grandfather Gustav Ferdinand Hertz (originally named David Gustav Hertz) (1827–1914) had been Jewish as a child, before his whole family had converted to Lutheranism in 1834).

[3][1][8] Hertz was concerned for his safety and, like his fellow Nobel laureate James Franck, was looking to move to the US or any other place outside Germany.

So he made a pact with three colleagues: Manfred von Ardenne, director of his private laboratory Forschungslaboratorium für Elektronenphysik, Peter Adolf Thiessen, ordinarius professor at the Humboldt University of Berlin and director of the Kaiser-Wilhelm Institut für physikalische Chemie und Elektrochemie (KWIPC) in Berlin-Dahlem, and Max Volmer, ordinarius professor and director of the Physical Chemistry Institute at the THB.

The objectives of their pact were threefold: (1) prevent plunder of their institutes, (2) continue their work with minimal interruption, and (3) protect themselves from prosecution for any political acts of the past.

[10] Before the end of World War II, Thiessen, a member of the Nazi Party, had Communist contacts.

Hertz was made head of Institute G, in Agudseri (Agudzery), about 10 km southeast of Sukhumi and a suburb of Gul'rips (Gulrip'shi).

In Institute A, Thiessen became leader for developing techniques for manufacturing porous barriers for isotope separation.

[12] In 1949, six German scientists, including Hertz, Thiessen, and Barwich were called in for consultation at Sverdlovsk-44, which was responsible for uranium enrichment.

[12] In that year, James Franck and Hertz were jointly awarded the Max Planck Medal by the Deutsche Physikalische Gesellschaft.