It is superfluous to add that Servia and Montenegro, Belgium and Luxemburg, could also produce some proofs of the defensive character of their policies. Thus, all the countries were on the defensive, none was the aggressor. But if that is so, then what sense is there in opposing the claims of defensive and offensive war to each other? The standards applied in such cases differ greatly, and are not frequently quite incommensurable. What is of fundamental importance to us Socialists is the question of the _historical_ rôle of the War. Is the War calculated to effectively promote the productive forces and the state organizations, and to accelerate the concentration of the working class forces? Or is the reverse true, will it hinder in this? This materialistic evaluation of wars stands above all formal or external considerations, and in its nature has no relation to the question of defense or aggression. And yet sometimes these formal expressions about a war designate with more or less truth the actual significance of the war. When Engels said that the Germans were on the defensive in 1870, he had least of all the immediate political and diplomatic circumstances in mind. The determining fact for him was that in that war Germany was fighting for her right to national unity, which was a necessary condition for the economic development of the country and the Socialist consolidation of the proletariat. In the same sense the Christian peoples of the Balkans waged a war of defense against Turkey, fighting for their right to independent national development against the foreign rule. The question of the immediate international political conditions leading to a war is independent of the value the war possesses from the _historico-materialistic_ point of view. The German war against the Bonapartist Monarchy was historically unavoidable. In that war the right of development was on the German side. Yet those historical tendencies did not, in themselves, predetermine the question as to which party was interested in provoking the war just in the year 1870. We know now very well that international politics and military considerations induced Bismarck to take the actual initiative in the war. It might have happened just the other way, however. With greater foresight and energy, the government of Napoleon III could have anticipated Bismarck, and begun the war a few years earlier. That would have radically changed the immediate political aspect of events, but it would have made no difference in the historic estimate of the war.