On War

The theater of war describes “such a portion of the space over which war prevails as has its boundaries protected” by using buildings or the natural elements of the terrain (155). An army is “the mass of troops in the same Theater of War” which is organized and led by a chief command (155). A theater of war and an army “mutually include each other” (156). In turn, a campaign is “the sum of all military events which happen in all Theaters of War in one year” (156). Occasionally, campaigns are interrupted by winter. They can also last longer than a year based on the logical conclusion.

The means of modern warfare presuppose that “the superiority in numbers becomes every day more decisive,” as does its “principle of assembling” (156). Numbers also matter because most European armies are comparable in organization, training, and equipment, so “[t]he character of modern battles is the result of this state of equality” (157). The absolute strength of an army is important in strategy regarding the objective. An army that lacks numbers must compensate with its energy.

In the early 19th century, the three arms of the military are the infantry, the cavalry, and the artillery. Combat generally features two types: using artillery fire or personal combat. Cavalry can only engage in personal combat and is primarily suited for attacks. Infantry can do both types of combat. It can also be mobile or stand firm when necessary. The benefit of using artillery is the effectiveness of its destructive power, especially in cases where a small country lacks men for military service. The drawback is its limited mobility. Cavalry “is the arm for movement and great decisions” (161).

Ranking them in terms of independence, they are as follows: infantry, cavalry, artillery, with the latter being the most dependent. However, the three arms act as part of a single whole. Infantry is the most important in the combination of the three arms, whereas “[c]avalry can the most easily be dispensed with” (159). It is possible to compensate for a lack in cavalry and artillery by strengthening the infantry.

The order of battle describes the “division and formation of the different arms into separate parts” of the entire armed forces (164). Both “division” and “disposition” are material, mathematical categories. “Disposition” describes the order of battle. An army is divided into smaller parts such as squadrons (dozens of men) and battalions (about a thousand). The bigger the armies, “the more they are distributed over wide spaces and the more diversified the action and reaction of the different parts amongst themselves” (165).

The combination of arms, the order of battle, and division are three principal points of interest here. Whereas divisions are important, they “must not be too great, otherwise disorder will ensue” (166). For example, a brigade may comprise 2-5,000 men. Army size determines numerical ranges. The combination of the three arms is relevant in strategic scenarios when certain parts of the army are frequently used. Disposition is “completely a tactical subject” pertaining solely to battles (168). In turn, “[t]he order of battle of any army is therefore the organization and disposition of it in mass ready prepared for battle,” satisfying both strategy and tactics (168).

Battles and intervals between battles are both states of importance. In the past, the interval state—of an army in its camp—was barely considered to be part of warfare. At the time of writing, “the situation out of battle is so thoroughly influenced by its connection with battle that the two states are in intimate correlation” (169). The interval state “is now partly regulated by the organization and regulations with which the army comes prepared from a state of peace,” as well as the tactical and strategic considerations (169).

The security of the armed forces depends on shelters, facilities of subsistence, rear security, proper troop distribution, “[a]n open country in front,” as well as “[s]trategic points […] where the troops are assembled (170). Such strategic points “must be of greater extent” than their tactical counterparts (170).

The first step is to use the advance guard “to watch the enemy” (171). Meanwhile, the reserves are in the rear in a separate position. Finally, “the covering of both wings of an army usually requires a separate disposition of particular corps” (171). Overall, “[t]he best criterion of skill in the disposition of an army lies in the proof that the distribution has been considered merely a condition” (172).

Advanced guards (the vanguard) and outposts pertain both to the realm of strategy and tactics. They are the “provisions which give form to the battle and ensure the execution of tactical plans” but also “are to be regarded as links in the strategic chain” (172). The advanced guard provides security for “the main body or center of the army” and is responsible for identifying “the approach of the enemy” (174, 172).

The need for advanced guard varies depending on many circumstances, such as the strength of an army. The strength of the advanced guard and the outposts also vary from a “considerable corps” to “mere outlying pickets” (173). Similar thinking applies to outposts. For example, Frederick the Great never used strong outposts and often encamped “close under the eyes of the enemy” (173).

Napoleon always relied on “a strong advanced guard” due to the large size of his modern army (174). At times, the center has a stronger vanguard because it is more numerous. The main army may be far removed from the vanguard. The advanced guard may pursue the enemy. In a retreat, the advanced guards become rearguards and may defend “the principal natural obstacles of the ground” (175).

The relationship “between outposts and stationary troops is similar to that between advanced guards and troops in motion” (176). As the main marching army needs rest at night, so does the advanced guard “and [so] always organize the outpost duty” (177). The terrain and climatic conditions of a country also play a role. For example, in winter, the advanced guard may be broken up “into a line of posts, because it is easier to find shelter for it in that way” (177).

The objective of the advanced corps “is to observe the enemy, and to delay his progress” (178). The latter “implies actual resistance” (178). Its character depends on many factors, such as the terrain and the enemy’s size and location. For example, the enemy itself is likely moving with an advanced guard. It is rare in such cases for such resistance to gain substantial time and may depend on the slow advance of the enemy, the resistance itself, and the retreat. Short fights may be repeated frequently to increase the duration. There are cases when advanced corps have the support of the cavalry positioned between the main troops and the former.

Time, place, and the size of the effective force all pertain to an army outside of combat. The army’s camp disposition, regardless of camp type (e.g. tents, bivouacs, huts), “is strategically completely identical with the combat which is contingent upon such disposition” (181). Tactically, however, the latter is not always the case. Since the late 1700s, armies have stopped using tents because they cause encumbrance; they now prefer open-air bivouacs or huts regardless of the season.

Clausewitz defines marches as “a mere passage from one position to another under two primary conditions” (182). These conditions are the “due care of the troops” to avoid squandering them and the “precision in the movements” (182). Historical examples include Frederick the Great’s rapid marches during the Seven Years’ War.

Occasionally, troops may be divided for marches “quite irrespective of that division of an army in separate parts which belong to its position” (182). This division improves mobility. At the same time, with the possibility of combat amidst a war, the marching columns “must be organized so that they could engage in an independent combat” (183). For example, the division may mimic the division of an army but on a smaller scale. Marches can be parallel (flank marches) or perpendicular.

Generally, marches on reasonable terrain require from eight to 10 hours for 8,000 men to cover the distance of two to three miles. In hilly terrain, this time increases to 10 to 12 hours. Exceptional marches may cover five to six miles in 16 hours for the same number of men. For example, in 1806, Napoleon covered approximately 30 miles in 10 days pursuing the Prussian Army. When long distances are involved, troops go from one cantonment (military camps) to another. Reducing the baggage load accelerates the marches.

Marches may have a detrimental impact on the troops. Clausewitz views marching “as an active principle of destruction, just as much as the combat” (188). The wearing down occurs through successive marches rather than a single counterpart. The physical and psychological strain, the need for shelter and nourishment, exacerbated illnesses without medical assistance, poor weather conditions, all contribute to the destructive character of marches. Marches similarly affect the cavalry horses, for instance, with sore backs. For instance, the Russian Army, when pursuing the retreating Napoleon from Kaluga to Vilnius, started with 120,000 men and was left with 30,000 men, with very few lost in combat (190).

Cantonments are indispensable in modern warfare “because neither tents nor a complete military train make an army independent of them” (190). Huts and bivouacs are insufficient. Occupation of cantonments may be hampered with the enemy’s movements or proximity. Clausewitz recommends using flourishing towns or villages to assemble the troops for this purpose. Such locations allow for freedom of movement.

Cantonments should be oblong-shaped, approaching a circle (or a square) so that the troops can concentrate at the central point. Natural obstacles may protect the cantonment. The advanced guard remains detached from the cantonment. Overall, a cantonment may cover an area of up to 30 square miles. An army should only be broken up in cantonments if it is necessary and if the enemy does so as well, and “[i]f the more immediate object with the army is completely limited to the maintenance of a strong position” (193).

Food supplies pose a significant problem in modern warfare for two reasons. First, the armies are large compared to the Medieval period. Their systematic arrangement with the rise of the separate military class also requires the same for subsistence. However, the large army size and its relative independence from the people create a problem of subsistence. Second is the “constant state of readiness for battle” of the modern period (194). Subsistence pertains not only to humans but to the horses of the cavalry, which require more food. Occasionally, horses can forage. Enduring privations should be a temporary, not a regular, scenario, despite this being “one of the finest virtues of a soldier” (196).

Subsistence comprises many forms. Sizeable, prosperous towns may support a large number of troops for several days, but small towns and villages are insufficient. Troops may buy or forcibly extract food themselves—the latter viewed “as an unavoidable evil” (199). Alternatively, cooperating with a local government, food may be requisitioned by it for the troops. This source of subsistence “has no limits except those of the exhaustion, impoverishment, and devastation of the country” (200). Clausewitz considers requisitioning the most promising system of the future.

Wagon trains with supplies may be “the most essential part” of the subsistence along with a soldier’s personal rations—both lasting for eight days in total (198). However, food made from flour requires transporting field ovens.

A base of operations is a source of reinforcements, subsistence, and communication typically located in the rear. A base is “the foundation of the army and of all its undertakings” (205). Even a portion of an enemy’s territory may serve this purpose. Provisions depots can typically be found in open towns. Because the base is the main source of resources and support, an army cannot change it on a daily basis. The latter “limits it always more or less in the direction of its operations” (206). The larger the army, the greater its dependence on the base.

Lines of communication are “[t]he roads which lead from the position of an army to those points in its rear where its depots of supply and means of recruiting and refitting its forces are principally united” (207). The lines of communication are “great vital arteries” linking the base and the army (207). Supplies include munitions, food, detachments, and field hospitals. The value of such a road depends on its direction, length, troop numbers, road conditions, general terrain, and the mood of the local population. Wide, serviceable roads with large, prosperous towns are optimal for this purpose.

“Country and ground” describe the terrain. Terrain generally pertains to tactics but may be linked to strategy. Topographical features such as marshes, hills, woods, and valleys affect military actions. Moderately cultivated countries are best suited for war. In contrast, thick woods and mountains may hinder its conduct, especially for the cavalry. For instance, thick woods reduce mobility.

An upward movement in certain types of terrain requires greater physical exertion than a downward movement. Topographical features may provide tactical advantages or disadvantages. For instance, in defense scenarios, the elevated ground offers tactical strength, a superior view, and hinders the approach of the enemy. The strategic advantage of elevated ground also depends on whether it is a single point or a larger area that can hold many troops for several combats. Offensive action may also benefit from the elevated ground. Overall, elevated ground with other topographical or geographical advantages in the favor of one side and disadvantages for the enemy (such as a large river) “may prove quite decisive” (214).