He began a career in journalism at the business department of
The New Republic. During the
First World War, he was a
military attaché in
Serbia, sparking a lifelong interest in American relations with foreign states. Armstrong retained an interest in the Balkans region throughout his career, publishing three books and upwards of ten
Foreign Affairs articles on the Balkans. He was also involved in American–Jugoslav societies. In 1922, at the request of editor
Archibald Cary Coolidge, Armstrong became managing editor of
Foreign Affairs, the journal of the newly formed
Council on Foreign Relations. Armstrong changed the name of the magazine from the
Journal of International Relations, which he found “unnecessarily dull” into
Foreign Affairs. Armstrong recruited his sisters, Helen and Margaret, to re-draw the logo. After Coolidge's death in 1928, Armstrong became editor, retiring from the position only in 1972, the fiftieth year of publication of the journal. Armstrong was an internationalist and proponent of open markets. During the Great Depression, he criticized isolationists and argued for America's engagement with the world. In the 1930s, Armstrong persistently warned about the rise of dictatorships in Europe, in particular Nazism. He authored six books condemning dictatorship, including the 1937 bestseller
We or They. He argued against neutrality in the years leading up to World War II. Armstrong was a prominent supporter of the Franklin Delano Roosevelt's 1936 presidential campaign. In 1933, Armstrong interviewed Adolf Hitler shortly after he was named Chancellor of Germany. It was one of Hitler's first interviews with a foreign journalist. During his interview, Armstrong injected multiple times when Hitler was answering. After the interview, Armstrong expressed dissatisfaction about Hitler and concern about what Hitler boded for world politics. Armstrong wrote early of the repression of political opposition underway in Germany, as well as the persecution of Jews. Armstrong was executive director of the Council on Foreign Relations. Armstrong wrote many books, including the early ''Hitler's Reich: The First Phase'' (published in July, 1933, by The Macmillan Company). He died after a long illness on April 24, 1973, at the age of 80. ==Personal life==