Konferenz von Évian
During World War I, Jaretzki served on the War Trade Board. He later acted as an adviser to the U.S. Delegation at the Évian Conference for Jewish refugees fleeing Nazi persecution. Following the conference, Jaretzki made four trips to Vienna to assist Jewish refugees and others emigrating from Germany on behalf of the American Jewish Joint Distribution Committee (AJJDC). He served as vice chairman of AJJDC and chaired their Committee on Refugee Aid in Central and South America. During World War II, Jaretzki served as special consultant to United States Secretary of War Henry L. Stimson.