Internationalist–defencist schism

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.