Journalism in Europe
Thompson boarded a ship to London in June 1920 to become a foreign correspondent, submitting articles to William Randolph Hearst's International News Service (INS). Ireland was in political ferment, so she went there, and on August 12 was the final person to interview the Sinn Féin independence leader Terence MacSwiney, who later that day was arrested for sedition; he died in prison on a hunger strike two months later.
The interview was sent by INS to American newspapers and led to Thompson being appointed Austria correspondent for the Philadelphia Public Ledger.
While working in Vienna, Thompson became fluent in German. She met and worked alongside correspondents John Gunther and G. E. R. Gedye. In 1925, she was promoted to Chief of the Central European Service for the Public Ledger. She resigned in 1927 and, not long after, the New York Evening Post appointed her head of its Berlin bureau. In Germany she witnessed firsthand the rise of the National Socialist or Nazi party. According to her biographer, Peter Kurth, Thompson was "the undisputed queen of the overseas press corps, the first woman to head a foreign news bureau of any importance".
During this time Thompson cultivated many literary friends, particularly among exiled German authors. Among her acquaintances from this period were Ödön von Horváth, Thomas Mann, Bertolt Brecht, Stefan Zweig and Fritz Kortner. She developed a close friendship with author Carl Zuckmayer. In Berlin she got involved in a lesbian affair with German author Christa Winsloe, while still married, claiming "the right to love".
Thompson's most significant work abroad took place in Germany in the early 1930s. In Munich, Thompson met and interviewed Adolf Hitler for the first time in 1931. This would be the basis for her subsequent book, I Saw Hitler, in which she wrote about the dangers of him winning power in Germany. Later, in a Harper's Magazine article in December 1934, Thompson described Hitler in the following terms: "He is formless, almost faceless, a man whose countenance is a caricature, a man whose framework seems cartilaginous, without bones. He is inconsequent and voluble, ill poised and insecure. He is the very prototype of the little man."
Biographer Kurth wrote: "Later, when the full force of Nazism had crashed over Europe, Thompson was asked to defend her 'Little Man' remark. 'I still believe he is a little man,' she replied. 'He is the apotheosis of the little man.' Nazism itself was 'the apotheosis of collective mediocrity in all its forms.' "