Born in Basel, Switzerland, Mohler studied art history, German literature, and philosophy at the University of Basel, where he briefly supported Communism. At the age of 20, he was drafted to the Swiss army, but instead in 1942 moved to National Socialist Germany, where he tried to join the Waffen SS, but was refused. When he returned to Switzerland, he was imprisoned for desertion.
After World War II, he returned to study in Berlin and completed his doctoral thesis Die Konservative Revolution in Deutschland 1918-1932 (The Conservative Revolution in Germany, 1918-1932). The aim of his thesis, whose fame helped spread the popularity of the concept of the Conservative Revolution, was not only to be a scientific study, but also to provide new pathways for old traditions for a non-National Socialist right in post-war Germany. It was published in 1950 as a book edition and is still considered a standard work, with several new editions published.
He worked as a secretary for Ernst Jünger, but increasingly felt that Jünger had become too moderate after the end of the war.
Mohler went on to work as a journalist for different newspapers. In 1960, he started working for the Carl Friedrich von Siemens Foundation and became its director.
He repeatedly spoke out against a legal ban on "Holocaust denial"
In the 1950s, Mohler contributed to journals such as Nation Europa. In 1970, he became a major contributing editor to the conservative monthly magazine Criticon. In his later years, he supported the Neue Rechte weekly paper Junge Freiheit. He actively promoted the Nouvelle Droite philosopher and his long-time friend Alain de Benoist.
In a 1995 newspaper interview, he answered the question of whether he was a fascist with "Yes, in the sense of José Antonio Primo de Rivera". When asked what fascism meant to him, Mohler said: “For me, fascism is when disappointed liberals and disappointed socialists come together for something new. The result is what is called a conservative revolution."
- Autobiographical Fragments
- Overcoming" Germany's Burdensome Past: The Heritage of Europe's "Revolutionary Conservative Movement"