Under Stimson, Johnson made a significant contribution when, as American Minister in China, he influenced Stimson's policy during the Manchurian incident, i.e., during Japan's invasion of Manchuria. His recommendation that the United States make a statement for upholding the terms of the Nine-Power Treaty left "a deep impression upon" Stimson and encouraged him "to pursue a course upon which he had already started" and which culminated in his letter to letter to US Senator William E. Borah, which was published on February 23, 1932.