General · EdgepediaSeptember 17, 20267 min read

Second International

The Second International was an international federation of socialist and labor parties, founded in Paris in 1889, that coordinated the socialist movement of Europe and beyond until it collapsed at the outbreak of the First World War in 1914 and was formally dissolved in 1923.¹^•² At its high point it affiliated more than three million members in socialist parties, plus many millions more in cooperatives, trade unions, and women's and youth organizations in more than 20 lands.³

Key fact	Detail
Founded	Congress opened in Paris on 14 July 1889, the centenary of the fall of the Bastille⁴
Founding attendance	Socialists of 23 countries, with the decisive support of the German Social Democratic Party (SPD)¹
Structure	For its first 11 years no executive body between congresses; permanent institutions only from 1900, when the International Socialist Bureau was seated in Brussels⁴^•¹
Lasting legacy	Declared May 1 an international holiday for labor, now known in many places as International Workers' Day, and launched the international campaign for the eight-hour working day⁵
Anti-war stance	The Stuttgart congress of 1907 resolved to prevent war "by all means" and, if war came, to use the crisis to overthrow capitalist rule¹
Collapse	German socialists voted war credits on 3 August 1914 and French socialists on 4 August; among the major belligerents only the Bolshevik deputies and several Menshevik deputies of Russia refused¹

Founding, 1889

The First International, the International Workingmen's Association, had dissolved at its Hague Congress in 1872, and for the next seventeen years socialist groups developed into organized national parties without an international center.⁴ Remnants of the old association held congresses at Berne (1876), Ghent (1877), Coire (1881), Paris (1883 and 1886), and London (1888), but these failed to reconstitute a genuine international body.⁶

Two rival congresses. The initial impetus for a new international came from the labor union movement, which wanted coordinated action on protective labor legislation, and the French Possibilists, a reformist party led by Paul Brousse, took charge of organizing a Paris congress for 14 July 1889, timed to the centenary of the storming of the Bastille.⁴ The French Marxists under Jules Guesde boycotted that gathering and convened a congress of their own. The Possibilist congress was numerically stronger, with about 600 delegates to the Marxists' 400, but the Marxist congress carried the prestige of the leading figures of world socialism and, decisively, the support of the German SPD, then the strongest working-class movement in the world. The Second International was established by the Marxist congress.⁴ Wilhelm Liebknecht of Germany and Édouard Vaillant of France were elected joint presidents of the founding congress.⁴

The founding congress passed two resolutions that shaped the movement's next quarter century. One committed socialist parties to campaign for the eight-hour workday and to support an international day of demonstrations on May 1, taking up a date the American Federation of Labor had nominated in 1888; the first international May Day followed in 1890.⁴ The other condemned standing national armies and called for their replacement with peoples' militias, on the reasoning that workers should not serve as cannon fodder for imperial expansion.⁴

Organization and internal conflicts

Unlike the tightly centralized First International, the new body recognized the autonomy of national parties and refused to intervene in their internal affairs; for its first eleven years it had no executive council at all.¹^•⁴ Permanent institutions came only after more than a decade: the International Socialist Bureau, created after the Paris congress of 1900, sat in Brussels with two delegates per country, supported by a permanent secretariat and executive committee; from 1905 Camille Huysmans served as secretary.¹ A Socialist Interparliamentary Commission followed in 1904, along with an international women's secretariat under Clara Zetkin and a socialist youth federation.¹

Exclusion of the anarchists. Membership was contested from the start. Anarchists disrupted the 1889 and 1891 congresses; the 1893 Zurich congress limited membership to organizations accepting political action and the class struggle, and the London congress of 1896 expelled them definitively.¹^•⁴ Trade unionists were admitted from 1893, with the Stuttgart congress of 1907 adding that unions should be guided by a socialist spirit.¹

The revisionist debate. Around the turn of the century Eduard Bernstein's "revisionism" challenged orthodox Marxism, with practical consequences such as the controversy over the French socialist Millerand's entry into a bourgeois government in 1899. Karl Kautsky brokered a compromise of principled condemnation with acceptance of exceptional circumstances, and Bernstein's revisionism was condemned outright at the Amsterdam congress of 1904.¹

The German SPD dominated the International throughout its existence, a preponderance visible already at the founding congress.⁴ The historian James Joll, author of The Second International 1889–1914, argued that German socialism's efforts to impose its theories and rules of action on other member parties retarded, for example, the development of a specifically French socialism.⁷ A study in Political Studies of the French and German parties, the two most powerful forces in the International, found that domestic factors, including dependence on the electorate, internal party structure, and party–trade union relationships, shaped their policy preferences and constrained the international organization.⁸

The war question and collapse, 1907–1914

War was the issue that eventually destroyed the organization. The Stuttgart congress of 1907 resolved to prevent war by all means and, if war broke out anyway, to use the crisis to bring down capitalist domination, an amendment moved by Lenin and Martov; the Copenhagen congress of 1910 specified the general strike, agitation, and popular action as the means, and the emergency Basel congress of 1912 assigned a particular role to the workers of Germany, France, and Great Britain.¹^•⁹

When the international crisis following the assassination at Sarajevo erupted in July 1914, the International Socialist Bureau, meeting in Brussels, called on the socialist parties to organize actions against the war. On 3 August the German socialists voted for war credits, and on 4 August the French followed. Among the great belligerent powers, only the five Bolshevik deputies and several Menshevik deputies in Russia refused such a vote.¹ The member parties had been pledged to resist war between capitalist states, and their adherence to their national governments broke the International.³ Writing in 1919, Lenin judged that if the First International had covered the growth of socialism in depth, the Second International had brought its expansion in breadth, and that the war had exposed the limits of that expansion.¹⁰

Aftermath and dissolution

The anti-war left met outside the organization, at the Zimmerwald conference of 1915 and the Kienthal conference of 1916.¹ In March 1919 the left wing constituted the Communist (Third) International in Moscow, defined from the beginning against the Second International's legacy of "social patriotism."¹¹ The Bureau's attempts to reunite the socialist parties at the Berne conference of February 1919 and the Geneva congress of July 1920 failed, and in February 1921 the pacifist center split away to form the "Two-and-a-Half International," the Community of Work of Socialist Parties.¹

The formal end came in May 1923, when the Berne International and the Vienna Union merged at a congress in Hamburg to form the Labour and Socialist International, the body that carried the socialist international tradition through to 1940.¹² Isaac Deutscher, the Polish-British historian and biographer of Trotsky, described the International of 1889 to 1914 as, for a quarter of a century, an impressive and in its way immensely influential organization, whose fate, like that of the First and Third Internationals, was shaped by the conflict between nationalism and internationalism in the labor movement.¹⁰

Legacy

The Second International's most durable acts were symbolic and practical rather than organizational. Its declaration of May 1 as an international day of labor demonstration, adopted in 1889 in commemoration of the Haymarket affair in Chicago and in support of the eight-hour day, made International Workers' Day a worldwide observance from 1890 onward.⁵^•¹³

References

Topic: Encyclopedia › Society and history › Politics and government › Political systems and ideas › Political parties and party families › Social-democratic and labour parties › Defunct social-democratic and democratic-socialist parties › Defunct social-democratic internationals and federations

Initially written Sep 17, 2026 · Reviewed: Sep 30, 2026; Oct 25, 2026 · Edited: Sep 30, 2026; Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026

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