The most visible sign of changing public attitudes toward the war came in the form of labor unrest. Labor leaders in all three countries, as well as most leaders of Socialist and labor parties, supported the war in 1914. But as the war dragged on in bloody fashion, conflict behind the screen of unity became more evident. Although labor unrest rose and then subsided in Britain and France in 1917, tensions escalated steadily and most significantly in Germany. By the spring of 1917, some members of Germany's Socialist party (SPD), led by Hugo Haase, broke away to advocate an end to the war without "annexations or indemnities." More radical Socialists, following future Communist leader Karl Liebknecht, had been arrested the year before for agitating openly against the war. As Germany moved into 1918, labor unrest began in a fashion that stretched down to the Armistice. Strikes in the first months of the year threatened arms production in Berlin and affected 250,000 workers there, as well as other workers in Hamburg and Leipzig. Miners struck in Silesia in July, and in the fall months the entire nation was engulfed in worker unrest compounded by military mutinies. The collapse of order on the German home front, including military mutinies, combined with the deteriorating position of the German army on the western front to force the government to end hostilities.