Foch had, for years, been teaching that fighting demands supreme flexibility, adaptability; that war is full of surprises which must be met as they arise; that morale, the spiritual force of an army, is subject to fluctuations caused by dozens of conditions which cannot be foreseen and must be overcome. The phrase oftenest on his lips was: "What have we to do here?" For, as he conceived warfare, officers and even privates must constantly be asking themselves that. One plan goes awry. Very well! we'll find a better. But Foch had not trained the German general staff. They made war otherwise. And well he knew it! Well he knew what happened to them when their "blue prints" would not fit unexpected conditions. He knew that they expected to take Nancy easily, that they were looking for some effort to defend it, but not for a French attack. They did not know his maxim: "The best means of defense is to attack." He attacked. His Twentieth corps fought its way through the center of the Bavarian army, into German Lorraine. Then something happened. Just what it was is not clear--but doubtless will be some day. The offensive had to be abandoned and the French troops had to withdraw from German soil to defend their own. How bitter was the disappointment to Foch we may guess but shall never know. But remaking plans in his genius. "What have we to do here?" he asked himself. Then, "in the twinkling of an eye," says one military historian, "General Foch found the solution to the defense problem wherewith he was so suddenly confronted when his offensive failed of support." XIII THE BATTLE OF LORRAINE What is known as the battle of Lorraine began at the declaration of war and lasted till August 26--though the major part of it was fought in the last six of those days. I shall not go into details about it here, except to recall that it was in this fighting that General Castelnau lost his oldest son, stricken almost at the father's side. A German military telegram intercepted on August 27 said: "On no account make known to our armies of the west [that is to say, the right wing, in Belgium] the checks sustained by our armies of the east [the left wing, in Lorraine]." So much depended on those plans which Castelnau and Dubail and Foch--and very particularly Foch!--had frustrated. Joffre realized what had been achieved. And on August 27 he issued the following "order of the day": "The First and Second armies are at this moment giving an example of tenacity and of courage which the commander-in-chief is happy to bring to the knowledge of the troops under his orders. "These two armies undertook a general offensive and met with brilliant success, until they hurled themselves at a barrier fortified and defended by very superior forces. "After a retreat in perfect order, the two armies resumed the offensive and, combining their efforts, retook a great part of the territory they had given up.