1 Soissons and Arras when I visited them were samples of the deadlock war; they were like Bloch come true. The living fact about war so far is that Bloch has not come true--_yet._ I think in the end he will come true, but not so far as this war is concerned, and to make that clear it is necessary to trouble the reader with a little disquisition upon war--omitting as far as humanly possible all mention of Napoleon's campaigns. The development of war has depended largely upon two factors. One of these is invention. New weapons and new methods have become available, and have modified tactics, strategy, the relative advantage of offensive and defensive. The other chief factor in the evolution of the war has been social organisation. As Machiavelli points out in his _Art of War_, there was insufficient social stability in Europe to keep a properly trained and disciplined infantry in the field from the passing of the Roman legions to the appearance of the Swiss footmen. He makes it very clear that he considers the fighting of the Middle Ages, though frequent and bloody, to be a confused, mobbing sort of affair, and politically and technically unsatisfactory. The knight was an egotist in armour. Machiavelli does small justice to the English bowmen. It is interesting to note that Switzerland, that present island of peace, was regarded by him as the mother of modern war. Swiss aggression was the curse of the Milanese. That is a remark by the way; our interest here is to note that modern war emerges upon history as the sixteenth century unfolds, as an affair in which the essential factor is the drilled and trained infantryman. The artillery is developing as a means of breaking the infantry; cavalry for charging them when broken, for pursuit and scouting. To this day this triple division of forces dominates soldiers' minds. The mechanical development of warfare has consisted largely in the development of facilities for enabling or hindering the infantry to get to close quarters. As that has been made easy or difficult the offensive or the defensive has predominated.