Internationalist and defencist were the broad opposing camps in the international socialist movement during and shortly after the First World War. Prior to 1914, anti-militarism had been an article of faith among most European socialist parties. Leaders of the Second International had even suggested that socialist workers might foil a declaration of war by means of a general strike. However, when war broke out in August 1914, the leaders of most European socialist parties rallied to the support of their respective countries, while a minority continued to oppose the war. Those in favour of their country's war efforts were variously called 'social patriots' or 'defencists'. Those opposed to the war called themselves 'Internationalists' and were often called 'defeatists' by their opponents. Division The 'defencist' camp included many venerable figures of European socialism: Jules Guesde and Édouard Vaillant in France, Gustav Noske and Friedrich Ebert in Germany, Georgi Plekhanov and Ekaterina Breshkovskaia among the Russians. Leaders of the anti-war 'Internationalist' camp included Jean Jaurès (who was murdered for his anti-war stance in 1914), Karl Liebknecht and Rosa Luxemburg, and later also Karl Kautsky and Eduard Bernstein, in Germany, Iulii Martov, Vladimir Lenin, Viktor Chernov and Mark Natanson among the Russians. The anti-war socialists held two international conferences at Zimmerwald and Kienthal in Switzerland in 1915 and 1916. The defencist–internationalist schism did not necessarily coincide with earlier, pre-existing splits, such as that between reformists and revolutionaries, Revisionists and orthodox Marxists, Bolsheviks and Mensheviks, etc. For example, Guesde and Vaillant in France had belonged to the intransigent, revolutionary left of the Socialist Party, and in 1914, anti-war sentiment was strongest on the far left. Yet both of these veterans were ardent supporters of the French war effort, while the old reformist leader Jaurès opposed the war. Likewise, Kautsky and Bernstein had been on opposite sides during the Revisionism controversy of the 1890s, Kautsky defending orthodox Marxism and Bernstein being the principal exponent of Revisionism; they both joined the anti-war faction. Meanwhile, the left wing Marxists Paul Lensch, Heinrich Cunow and Konrad Haenisch went on to form the Lensch-Cunow-Haenisch group, which argued that the First World War was a revolutionary war against the liberal capitalism of the Triple Entente. 'Defencism' and 'Internationalism' were broad categories; within each camp, there were further differences and divisions. Out-and-out 'Social Patriots' who supported their countries' war efforts unconditionally, including territorial ambitions, were fairly rare, though they included some