D’you know (well, yes, yes you do, most likely, being a historian) that really was the plan of the then international socialists. It was so obviously, so painfully a war in the interest of capitalism and large capital and against humanity in general that they thought that they might get it to stop by just refusing. The great proletariat masses made it possible, after all, and it could not proceed without their consent.
But the attempt failed. Narrow national interest won.
I often wonder what might have happened if they managed to agree and blocked the Great War. Hah. Now there’d be a alternate history that’d never make it to TV.