A scholar and author originally from Poland, he was the winner of a National Book Award in history and a National Jewish Book Award in the Holocaust category for his monograph titled Judenrat: The Jewish Councils in Eastern Europe Under Nazi Occupation published in New York by Macmillan in 1972.

After his graduation, Trunk taught history in various city schools and was associated with the work of historians from YIVO in Warsaw.

He moved to New York City a year later to work at YIVO, where he became a chief archivist in 1971.

[2] Trunk was the author of numerous articles and studies on the Holocaust in English and Yiddish, including his nominal Jewish Response to Nazi Persecution published in 1979.

[2][clarification needed] Trunk's ground-breaking research into the wartime activities of the Jewish Ghetto Councils was described as follows in the Kirkus Reviews:[6] In an understated, matter-of-fact way Trunk documents the prevalent favoritism and corruption of many Council members -- he always reminds us that no blanket generalizations hold -- and shows how Council taxes, which in large part went to pay salaries, fell most heavily on the poorest ghetto inhabitants.