Context: on the eve of WWI the SPD in Germany was the most successful and powerful socialist party in the world with a good shot of taking power in a couple years. Like the other socialist parties it was officially opposed to imperialist wars, but when it came down to it, barring a few principled individuals like rosa Luxembourg, the party voted yes on war bonds out of fear of looking unpatriotic, signing the blank check the kaiser issued and sending Germany into WWI which of course worked out great for the working class and Germany as a whole...
Wait 'til you see what they did after the war!