In 1899, Chesterton wrote a poem entitled “To a Certain Nation” as a reproach to France for the injustice done to Captain Dreyfus. However, Chesterton soon reversed his opinion. In 1906, Chesterton added a note to the second edition of The Wild Knight which reveals that by 1906 he had started to change his position about where the greater injustice lay. The note stated that whilst “there may have been a fog of injustice in the French courts; I know that there was a fog of injustice in the English newspapers.” According to the note, he was unable to reach a “proper verdict on the individual,” which he largely attributed to the “acrid and irrational unanimity of the English Press.” Chesterton maintained this antipathy about Dreyfus throughout his life. In letters to The Nation in 1911, Chesterton referred to the Jew “who is a traitor in France and a tyrant in England,” and stated that in “the case of Dreyfus,” he was quite certain that “the British public was systematically and despotically duped by some power – and I naturally wonder what power.” He argued in 1928 that Dreyfus may or may not have been innocent, but that the greater crime was not how he had been treated at trial but how the English newspapers buried the evidence against him. According to Chesterton, “the English newspapers incessantly repeated that there was no evidence against Captain Dreyfus. They then cut out of the reports the evidence that he had been seen in German uniform at the German manoeuvres; or that he had obtained a passport for Italy and then gone to Germany.” Chesterton stated that when he discovered this, “something broke inside my British serenity; and a page of print has never been the same to me again.” In another article Chesterton did defend a Jew, Oscar Slater, from the charge of murder, thereby demonstrating that Chesterton was not unremittingly antisemitic. However, seemingly unwilling to defend one Jew without sniping at another, he again repeated the accusation that the English newspapers left out “evidence that Dreyfus had appeared in German uniform at the German manoeuvres” In another article, this time published in 1933, he criticised Hitler and Nazi antisemitism (something he did on a number of occasions as his defenders have pointed out), whilst yet again asserting that the English “were never told, for instance, that Dreyfus had got leave to go to Italy and used it to go to Germany; or that he was seen in German uniform at the German manoeuvres.”
Chesterton’s unfavourable presentation of Captain Dreyfus can also be seen in one of his fictional works: “the Duel of Dr. Hirsch.” In this Father Brown short story, originally published in 1914, the Jew, Dr. Hirsch/Colonel Dubosc, is modelled on a diabolic composite of Judas Iscariot, Captain Dreyfus, Dr. Jekyll and Mr. Hyde. The Jew in the story sets up a second Dreyfus affair using false evidence, playing simultaneously the role of the accused villain (Hirsch) and the accusing hero (Dubosc). Hirsch succeeds in his complex scheme to be vilified as a traitor who has given military secrets to the Germans (the accuser being his own alter-ego), and then vindicated and heralded as a hero (whilst his alter-ego slinks away). Bryan Cheyette observes that Father Brown – a reoccurring hero in many of Chesterton’s short stories, who, as Dale Ahlquist has observed, reflects “Chesterton’s own moral reasoning” – “admits to being morally confused over whether Hirsch is guilty and compares it with his ‘puzzle’ over the ‘Dreyfus case.’” 
At the end of “the Duel of Dr. Hirsch,” the Jewish villain is seen by Father Brown’s assistant (M. Hercule Flambeau), half way through his metamorphosis from Colonel Dubosc to Dr. Hirsch. According to the narrator of the story, Hirsch’s face, with its “framework of rank red hair,” looked like “Judas laughing horribly and surrounded by capering flames of hell.” This final image of Hirsch is reminiscent of the so-called “diabolist” that Chesterton claimed he once knew, with “long, ironical face … and red hair,” and when seen in the light of the bonfire, “his long chin and high cheek-bones were lit up infernally from underneath; so that he looked like a fiend staring down into the flaming pit.”
In conclusion, it does seem, on the surface, that the Dreyfus Case was a significant turning-point in Chesterton’s discourse about Jews (from sympathetic in 1899 to hostile by 1906). He claimed in 1928 that the Dreyfus Case marked “a great date in [his] life.” He stated that: “it was the last time I was deceived. Up to the time of the Dreyfus Case, I had believed like a child, or like a great mass of the public, that our press merely recorded what really happened; that no journalist but a chance criminal would suppress a vital fact.” It thus seems, as Julia Stapleton has rightly noted, that it never occurred to Chesterton to question whether there was any truth in the highly dubious allegations that Dreyfus was seen “in German uniform at the German manoeuvres,” or whether the claims “were suspect and thus beyond the realms of responsible journalism.” 
Notes for G. K. Chesterton and the Dreyfus Affair
 G. K. Chesterton, “The Duel of Dr. Hirsch,” in G. K. Chesterton, The Complete Father Brown Stories (London: Wordsworth Classics, 2006), 213-224; Bryan Cheyette, Constructions of “the Jew” in English Literature and Society: Racial Representations, 1875-1945 (Cambridge: Cambridge University Press, 1993), 192-193; Dale Ahlquist, G. K. Chesterton: The Apostle of Common Sense (San Francisco: Ignatius Press, 2003), 166.
 G. K. Chesterton, “Dreyfus and Dead Illusions,” Straws in the Wind, G.K.’s Weekly, 25 February 1928, 993; Julia Stapleton, Christianity, Patriotism, and Nationhood: The England of G. K. Chesterton (Plymouth: Lexington Books, 2009), 46.