A Nazi sympathizer, Ferdonnet was known for having published an anti-semitic book, La Guerre juive (The Jewish War).
He relocated to Germany in the 1930s and was an employee of Radio-Stuttgart where he worked on propaganda broadcast in French and aimed at promoting the Nazi regime and demoralizing French troops and civilians.
[2] The previously obscure Ferdonnet became famous and notorious, and claimed that Britain would let France fight and die on its behalf: "Britain provides the machines, France provides the bodies".
[3] After the fall of France, transmissions in French were progressively discontinued and Ferdonnet stopped working for Radio-Stuttgart around 1942.
He was arrested after the fall of Nazi Germany and executed for treason in 1945.