In detailed tactical estimates the commander requires an exhaustive comprehension of the fighting capabilities of his own and the enemy armed forces, because his selection of physical objectives and his use of relative position are affected by such considerations. This is manifestly true for studied tactical estimates made in advance to meet contingencies, but its import is not always fully understood in its bearing on the unfolding situation after the battle begins. At that time, the most precise knowledge is called for, under the then rapidly changing conditions. (Chapter IX.) In the Form treated herein, those matters particularly applicable to broad estimates are included under "general factors". These are followed by the factors more directly applicable to the armed forces. (a) General Factors. (i) Political Factors. The prosecution of the war is directly influenced by such internal conditions as the strength of the national government and its capacity for unified effort, the moulding and maintaining of a firm public opinion in support of war aims, the neutralization of subversive propaganda, and the degree to which the government can make available necessary resources, both domestic and foreign. External relations modify the conduct of war, always affecting broad estimates of the employment of national forces. The wartime factors which influence these relations include the effect of the clash between foreign opinion and national policy, the national bias of interested neutrals and of unneutral non-belligerent governments, and the normal attitude of such neutrals and non-belligerents toward each belligerent. The diplomatic skill of the opposing governments and the ability of propaganda to sway public opinion abroad may well determine the manner in which neutrality will be enforced. Alliances, including those that are known and those that are secret, directly influence an estimate. When a war of any importance breaks out in any part of the world, all States are affected to some degree. One may have an alliance which, though not requiring active participation in the war, will call for collaboration with the efforts of a belligerent. Another alliance may require active participation, while still another State may attempt to maintain strict neutrality. Every State remaining at peace will thus be in a status ranging from that of a non-belligerent, with more or less close ties to one of the contestants, to a position of strict impartiality. The estimate of the international situation becomes more complex as the magnitude of the war increases. A correct appreciation of the status of each State concerned is of first importance in any broad estimate of the conduct of war.