In face of that necessity the choice as to which of the two should be attempted first was not a choice which admitted of debate. Defeat of the French forces in the field must be first. Without it, the investment of Paris had clearly become an impossibility. How far it had become an impossibility will be realised by looking at the position of the German armies. Five of them were echeloned across France from Creil, north-east of Paris, to near the southern point of the Argonne. The army of von Kluck was between Creil and Soissons, with advanced posts extended to Meaux on the Marne. The army of von Bülow was between Soissons and Rheims, with advanced posts pushed to Château-Thierry, also on the Marne. The army of von Hausen held Rheims and the country between Rheims and Chalons, with advanced posts at Epernay. The army of Duke Albert, with headquarters at Chalons, occupied the valley of the Marne as far as the Argonne. The army of the Crown Prince of Prussia, with headquarters at St. Menehould, held the Argonne north of that place, with communications passing round Verdun to Metz. If the line formed by these armies be traced on the map, it will be found to present from Creil to the southern part of the Argonne a great but somewhat flattened arc, its curvature northwards. Then from the southern part of the Argonne the line will present a sharp bend to the north-east. Now these five armies, refortified by reserves, comprised nineteen army corps, plus divisions of cavalry--a vast force aggregating well over one million men, with more than 3,000 guns. Powerful as it appeared, however, this chain of armies was hampered by that capital disadvantage of being held fast by the tail. Held as it was, the chain could not be stretched to attempt an investment of Paris without peril of being broken, and the great project of defeating and enveloping the Allied forces was impossible. No question was during the first weeks of the war more repeatedly asked than why, instead of drafting larger forces to the frontier of Belgium, General Joffre should have made what seemed to be a purposeless diversion into Upper Alsace, the Vosges, and Lorraine. The operations of the French in those parts of the theatre of war were neither purposeless nor a diversion. On the contrary, those operations formed the crux of the French General's counter-scheme. Their object was, as shown, to prevent the Germans from making an effective attack on the fortified frontier. General Joffre well knew that in the absence of that effective attack, and so long as the German echelon of armies was pinned upon the frontier, Paris could not be invested. In short, the effect of General Joffre's strategy was to _rob the Germans of the advantages arising from their main body having taken the Belgian route_.