In 1928 Chanler wrote to then-governor of New York, Franklin D. Roosevelt, on his preoccupation with Jewish conspiracy, and stated that he was in confidential communication with anti-Jewish Arab leaders including the Grand Mufti of Jerusalem. In 1933 he wrote to his sister Elizabeth Astor Winthrop Chanler on the "centralized Jewish control of world affairs," stating his belief that the British cabinet was under the control of the Fabian Society and Baron Israel Moses Sieff, who were enacting a secret plan to "Bolshevize" Great Britain and the United States, "which will result in the absolute loss of individual independence."