In January 1871, as Paris lay besieged by the German army, Tridon collaborated with Édouard Vaillant, Jules Vallès and others in writing the Affiche rouge (red poster), which denounced the Thiers government, called for the establishment of an autonomous Paris Commune and put forward three main demands: general requisitioning of all human and material resources, free rations for all, and fighting to the utmost against the siege.
Tridon joined the Republican Central Committee of the Twenty Districts, in which Blanquists, Proudhonists, Jacobins and various other radicals, who had until recently been rivals, collaborated.
Tridon was among the minority in the Council who voted against the creation of a Committee of Public Safety, modelled on that of the first French Revolution, which had unleashed the terror.
Tridon's opposition to the Committee of Public Safety made him a strange bedfellow of many of his erstwhile rivals, Proudhonists like Eugène Varlin, and put him at odds with Jacobin socialists like Félix Pyat and Théophile Ferré, whose ideology might on the whole have seemed closer to his own.
Apparently Tridon had long been suffering from some sort of nervous disorder; the massacres of the Bloody Week (Semaine sanglante) precipitated an emotional crisis.
Proudhon, for example, complained in his diaries that France was overrun with Jews and foreigners, while Blanqui, in his letters, sometimes used the term 'shylock' as a synonym for capitalist or usurer.
[1] However, in the late nineteenth century, some veterans of the previous revolutionary movements[clarification needed] expressed a more vehement and public anti-Semitism, usually combined with fierce nationalism.
Nevertheless, he had a posthumous influence on them, primarily through a manuscript he had written but not published in his lifetime: Du Molochisme Juif: Études Critiques et Philosophiques (On Jewish Molochism: Critical and Philosophical Studies.)
In the book, Tridon proclaimed the superiority of 'Indo-Aryan' over 'Semitic' culture and traced Judaism back to the ancient worship of the god Moloch, who, he claims, demanded human sacrifice.
Christianity and Islam, as derivatives of Judaism, are also condemned; by contrast, 'Aryan' culture and western civilization are said to have culminated in the scientific rationalism of the Enlightenment and its corresponding atheism.
Writers who value his contributions to French socialism tend not to dwell on the Moloch book, while Tridon's anti-Semitism makes him one of the patron saints of far right movements that have much less use for his involvement in such organisations as the First International.