 Kunyange zvakadaro, pakatanga hondo muna 1914, mapato akawanda eSocialist eInternational akapesana uye akatsigira hurumende dzawo muhondo yacho, achitengesa tsika dzawo dzeinternationalist uye zvichitungamirira pakuparara kweSecond International. Uku kutengesa kwakasunda nhume shomanene dzinorwisana nehondo dzakanga dzasara mukati meSecond International kuronga International Socialist Conference paZimmerwald, Switzerlandmuna 1915. Yainzi Zimmerwald Conference, chinangwa chayo chakanga chiri chokugadzira gadziriro yokushora hondo. Musangano wacho wakanga usingakwanisi kusvika pachibvumirano pazvinhu zvose, asi pakupedzisira wakakwanisa kubudisa Zimmerwald Manifesto, iyo yakanga yakanyorwa naLeon Trotsky. Nhume dzakarerekera kuruboshwe zvikurusa uye dzakasimba zvikurusa dzorudzi rwomunyika yose pamusangano wacho dzakarongwa dzakapoteredza Lenin neRussian Social Democrats, uye dzinozivikanwa seZimmerwald Left. Ivo vakashurikidza zvinotyisa hondo uye izvo ivo vakarondedzera sevasonganiri vezvamatongerwe enyika vanonyengera veSecond International, avo vakakurumidza zvikuru kusiya nheyo dzavo dzamarudzi ose ndokuramba kushora hondo. Zvisarudzo zveZimmerwald Left zvakakurudzira vashandi vose vezvematongerwe enyika avo vakanga vakazvipira kumitemo yenyika yose yezvematongerwe enyika kurwisana nehondo uye kuzvipira kumutsiridzo wevashandi vomunyika yose. 