The International Socialist Commission, also known as the International Socialist Committee or the Berne International was a coordinating committee of socialists parties that adhered to the idea of the Zimmerwald Conference of 1915.
The Zimmerwald Conference elected Angelica Balabanoff, Odino Morgari and Charles Naine to the Commission, with the Swiss socialist Robert Grimm as chairman and Balabanoff as interpreter. The Committee was charged with setting up a temporary secretariat and publishing a bulletin. The ISCs initial purpose was to act as an intermediary between the affiliated groups in their struggle for peace. It was not to act as a replacement for the International Socialist Bureau and dissolve as soon as the ISB could begin functioning normally. Other adherents of the Zimmerwald movement, such as Vladimir Lenin, saw it as the beginning of a new International.
The Commissions activity in the first months of its existences consisted of translating the manifesto and resolutions of the conference and distributing them as widely as possible. To that end they first forwarded copies of the first number of their Bulletin to the socialist and trade union papers of the neutral countries. Within the belligerent countries the ISC was able to have the full documents published in Italy, Russia, France, England and Bulgaria but only summaries in Austria and Germany. They also sent a circular to all the parties adhering to the ISB announcing their existence and the objects of the group. Only the Danish party replied, officially disapproving of the Zimmerwald venture. However, at the Congress of the Swiss Socialist Democratic Party at Aarau November 20–21, the delegates declared their adherence to the ISC and granted the organization 300 francs.
On September 27, 1915, ISC sent out a confidential circular (which was nevertheless leaked to the unfriendly press) suggesting that the adhering groups appoint up to three extra delegates to join the Commissioners as part of an Enlarged Committee. The first session of this Enlarged Committee of the International Socialist Commission was held in Berne February 5–8, 1916. No official list of attendees was published and sources disagree about who was present. Fainsod lists the following: Robert Grimm and Fritz Platten from the Swiss Social Democratic Party; Lenin and Zinoviev from the Bolsheviks; Julius Martov and Pavel Axelrod from the Mensheviks; David Riazanov of the Mezhraiontsy (also known as the Inter-District Committee); Feliks Kon and Pawel Lewinson from the Polish Socialist Party - Left; Bertha Thalheimer, Adolf Hoffman and Georg Ledebour, dissidents from the German Social Democratic Party; Serrati, Modigliani and Angelica Balabanoff from the Italian Socialist Party; Christian Rakovsky from the Social Democratic Party of Romania and Edmondo Peluso from the Social Democratic Party of Portugal. However, the Hoover Institution adds Alexander Martynov, for the Mensheviks, Franz Koritschoner, a dissident member of the Social Democratic Party of Austria; Henri Guilbeaux, editor of the Demain; Karl Radek of the Social Democracy of the Kingdom of Poland and Lithuania; and Willi Münzenberg, secretary of the International Socialist Youth League. Furthermore, there was apparently a representative of the Dutch Zimmerwaldists present, or one of the above may have held the Dutch mandate. The identity of this person remains unclear.