After the war he worked as a journalist. Violently anti-Semitic, he joined the British Union of Fascists in 1933. Two years later two secret agents from Nazi Germany established the anti-Semetic Nordic League. The organization was initially known as the White Knights of Britain or the Hooded Men. Archibald Ramsay soon emerged as the leader of this organization. Chesterton became a member and wrote several pamphlets for the organization.
In 1937 Chesterton published a sympathetic biography of Oswald Mosley entitled Portrait of a Leader. He was also editor of Lord Lymington's right-wing journal, New Pioneer.
Chesterton considered that Mosley was not anti-Semetic enough and in 1938 several members of the British Union of Fascists left the organization and founded the National Socialist League. This included Chesterton, John Becket and William Joyce. Chesterton became increasingly extremist in his views and at a meeting of the Nordic League in May 1939 he suggested that the lamp-post was "the only way to deal with the Jew".
Archibald Ramsay founded a secret society called the Right Club in May 1939. This was an attempt to unify all the different right-wing groups in Britain. Or in the leader's words of "co-ordinating the work of all the patriotic societies". In his autobiography, The Nameless War, Ramsay argued: "The main object of the Right Club was to oppose and expose the activities of Organized Jewry, in the light of the evidence which came into my possession in 1938. Our first objective was to clear the Conservative Party of Jewish influence, and the character of our membership and meetings were strictly in keeping with this objective."
Members of the Right Club included Chesterton, William Joyce, Anna Wolkoff, Joan Miller, Francis Yeats-Brown, E. H. Cole, Lord Redesdale, 5th Duke of Wellington, Aubrey Lees, John Stourton, Thomas Hunter, Samuel Chapman, Ernest Bennett, Charles Kerr, John MacKie, James Edmondson, Mavis Tate, Marquess of Graham, Margaret Bothamley, Earl of Galloway, H. T. Mills, Richard Findlay and Serrocold Skeels.
During the Second World War Chesterton went to live in Africa. He returned to Britain after the war and remained active in extreme right-wing organizations. This included the League of Empire Loyalists (1954-1967), the Racial Preservation Society and the National Front.
Arthur Kenneth Chesterton died on 16th August, 1973.