In 1941, Thompson wrote "Who Goes Nazi?" for "Harper's Magazine". She was a keynote speaker at the Biltmore Conference, and by war's end was regarded as one of the most effective spokespersons for Zionism. Thompson switched her views round radically after a trip to Palestine in 1945, and ran into difficulties, including accusations of anti-Semitism, which she strongly rebuffed, after being warned that hostility toward Israel was, in the American press world, "almost a definition of professional suicide". She eventually concluded that Zionism was a recipe for perpetual war.