3. The position of France relatively to Germany and Spain illustrates also the question of communications. “Communications” is a general term, designating the lines of movement by which a military body, army or fleet, is kept in living connection with the national power. This being the leading characteristic of communications, they may be considered essentially lines of defensive action; while interior lines are rather offensive in character, enabling the belligerent favored by them to attack in force one part of the hostile line sooner than the enemy can reinforce it, because the assailant is nearer than the friend. As a concrete instance, the disastrous attempt already mentioned, of Spain in 1639 to send reinforcements by the Channel, followed the route from Corunna to the Straits of Dover. It did so because at that particular moment the successes of France had given her control of part of the valley of the Rhine, closing it to the Spaniards from Milan; while the more eastern route through Germany was barred by the Swedes, who in the Thirty Years’ War were allies of France. The Channel therefore at that moment remained the only road open from Spain to the Netherlands, between which it became the line of communications. Granting the attempt had been successful, the line followed is exterior; for, assuming equal rapidity of movement, ten thousand men starting from central France should reach the field sooner. The central position of France, therefore, gave both defensive and offensive advantage. In consequence of the position she had interior lines, shorter lines, by which to attack, and also her communications to either front lay behind the front, were covered by the army at the front; in other words, had good defense, besides being shorter than those by which the enemy on one front could send help to the other front. Further, by virtue of her position, the French ports on the Atlantic and Channel flanked the Spanish sea communications. At the present moment, Germany and Austria-Hungary, as members of the Triple Alliance, have the same advantage of central and concentrated position against the Triple _Entente_, Russia, France, and Great Britain. [Illustration: [Map]]