He returned to Paris and attempted to convince the British and American embassies to provide neutral intervention in the conflict, even considering travelling by hot air balloon to the Prussian king himself. On the death of his brother-in-law in the Vosges, Passy left Paris once again, disheartened that the could not stop the war. With Passy having adamantly renounced the earlier group, it is understandable that Edmond Potonié was one of the main opponents of the . He believed it not to be a serious peace society due to their vastly-differing opinions on the speed of change: he believed that only rapid societal change would bring about peace, whereas Passy's group advocated a calmer legalistic approach. Other protest against the came from religious groups, with Hyacinthe Loyson being denounced by the right-wing journalist Louis Veuillot as part of a "Protestant front": efforts to recruit more Catholics to the cause largely failed. The received monetary support from notable liberals, such as John Stuart Mill (who joined on 4 August 1867) and Jean Dollfus. Subscription rates for its 600 members allowed the 's treasury to have six thousand francs in 1868: founding members paid roughly one hundred francs, while associates paid five francs. After the 's collapse following the Franco-Prussian War, peace activism in Europe gained a rejuvenation after the successful arbitrations between Britain and the United States in Geneva. Daniël van Eyk, Philip Johannes Bachiene, and Samuel Baart de la Faille founded a Dutch group on the ideas behind Passy's in 1871, and Masonic lodges began to undertake peace projects. Passy noticed this renewed belief in peace, and in 1872 he began working on reviving the . He explained the two paths which society could take: He was aware that his favoured path, the latter, would not happen immediately or even in the near future, but set about creating a new French peace society to promote arbitration, the (French Society of Friends of Peace). Several other groups considering arbitration and the development of international law appeared during this time, including the (Association for the Reform and the Codification of the Law of the People; later the International Law Association) in 1873, which Passy and Henry Richard were involved in. The meetings, involving discussions on ways to reduce friction among different communities, were a way to enhance the conversations that Passy thought important for developing international co-operation. Noticing the growth and popularity of the peace movement, members of the arranged a congress at the 1878 Paris Exposition, however they warned attendees not to raise "unpleasant" and provocative issues. 13 different nations were present among the 150 delegates, although 95 were from France.