(Note.—The preparation of this problem will require considerable work on the part of the Director in order to get all of the features of the position worked out in detail so as to be able to include them in the order to the company commanders. If it is practicable to do so the boundaries of the battalion sector, together with the location of the machine guns and howitzer units and the battalion C. P., should be marked with flags. This will save many questions during the Terrain Exercise and save a lot of time. It will give the members of the class a much better idea of the set-up and they will be able to proceed with the solution of their part of the problem more readily.) Procedure The members of the class are assembled in the vicinity of (_x_). The Director distributes the sheets containing the special situation Blue and reads it aloud. The members of the class follow from the copy in their possession. The places, localities and areas referred to are pointed out in detail. The Director will call upon one or more members of the class to state his understanding of the tactical situation and this process is continued until he is satisfied that all members know the details and are ready to proceed with the solution. Explanation _The Director_: “Before going further with the problem I want to make some remarks on the general subject of the defensive and some with reference to the part that the battalion and its component parts plays in it. The problem under consideration is that of a passive defense. Our troops have made such rapid progress that the rear echelons have not been able to keep up. The enemy has been falling back on his reserves and naturally his defense is stiffening all along the line. The time has arrived when it is necessary for us to stop for a period; reorganize our forces, which have been more or less disorganized by our successes; bring up our rear echelons; and prepare to continue the advance. During this period we must so organize our position that the enemy will have little chance for success should he decide to attack with a view to interfering with our arrangements. “Our attacking troops have now arrived on a general line where a defensive position may be taken up and the high command has ordered such action. We do not want to give up any ground that has been gained that is suitable for our purpose. Having this principle in mind Major A has decided to organize and hold the ground that is now occupied by the support echelon of the 2nd Battalion.” Procedure _The Director_: “Lieutenant Williams, what factors exercise the greatest influence in the selection of a defensive position?”