Book II: On the Theory of War

Clausewitz defines war in its literal sense as fighting, which is a trial of strength between moral and physical forces, with the condition of the mind having the most decisive influence.

Though weapons and equipment have undergone great alterations, the conception of fighting remains unaltered and constitutes the essence of war.

Preparations like arming and equipping are distinct from fighting itself; mere wrestling qualifies as fighting despite lacking weapons, showing that fighting is independent of specific armaments.

Fighting remains distinct from other activities because it operates in the special element of danger, a characteristic that necessitates a clear separation from preparatory activities.

A sharp distinction must be drawn between fighting and its preparation because eminence in one field does not guarantee competence in the other.

The Art of War, in its proper sense, is the art of using given armed forces in fighting, which is best called the 'Conduct of War,' distinct from the wider sense encompassing the creation and maintenance of forces.

Sound military theory must separate preparation of forces from their use in combat, basing itself on general means and their actual results rather than assuming specifically suited forces.

The conduct of war divides into tactics, which concerns the formation and conduct of single combats, and strategy, which concerns the combination of combats toward the ultimate war objective.

Clausewitz defines tactics as the theory of using military forces in combat and strategy as the theory of using combats for the war's object.

A single combat unit extends spatially as far as personal command reaches and temporally until the crisis of combat is fully passed, with some border cases admitting classification as either tactical or strategic.

Some military activities may reasonably be classified as either tactical or strategic, such as extended chain formations or multi-point river crossings, and this does not undermine the classification system.

The tactics-strategy classification encompasses only the use of military force, excluding various supporting activities related to the maintenance of that force.

Activities maintaining military forces—subsistence, medical care, supply—are to be excluded from the conduct of war proper because they are fundamentally different from the use of forces, despite constant reciprocal action.

Maintenance activities are rightfully excluded from the theory of conduct of war because theory must eliminate heterogeneous elements, and these activities are essentially different from the use of troops.

All military activities outside combat are threads that end in it and must appoint an object to themselves in accordance with the combat's laws, creating a unified system.

Marches possess a dual nature: they are integral to combat when included in maneuvers, but outside combat they serve as instruments of strategy for executing plans about when, where, and with what forces battles occur.

A march outside combat, though primarily a strategic measure, must also follow tactical rules because the armed force executing it may become involved in combat at any moment.

Prescribing a route to position forces for potential combat is strategic; determining march arrangements for combat readiness is tactical, illustrating the interplay between the two domains.

The specific arrangement of a marching formation reflects readiness for combat and is therefore tactical in nature, representing the preliminary disposition for battle.

Because strategy uses marches to arrange and direct its active elements (combats), marches are often substituted for combats in theoretical discourse, though the underlying reality remains combat.

Theorists err when they attribute independent power to strategic combinations and marches, concluding that enemies can be defeated without fighting, forgetting that combats are the real foundation.

Certain aspects of marches—accommodations, bridge construction, roads—are merely conditions or prerequisites and do not belong to the theory of conduct of war even when closely connected with troops.

Camps represent both a state of troop restoration and a strategic appointment of battle, containing the fundamental lines of battle and serving as essential parts of both strategy and tactics.

Cantonments replace camps for better troop refreshment, functioning as strategic subjects regarding position and extent, and tactical subjects regarding internal organization for combat readiness.

While camps and cantonments typically combine troop recuperation with other objectives like covering territory or holding positions, recuperation alone can be a sufficient strategic object.

When camps and cantonments generate activities purely for troop maintenance—such as constructing huts or providing subsistence—these fall outside the scope of strategy and tactics.

While entrenchment planning and preparation are tactical subjects forming part of battle order, the actual execution of construction is excluded from conduct theory because organized armies are presumed to possess such capabilities.

Troop subsistence is the primary maintenance activity, requiring near-daily attention to individuals, and permeates strategic planning more than tactical conduct, though it remains essentially different from troop use.

Though subsistence remains a completely different activity from troop use, it frequently influences strategic planning and is often the determining factor in campaign design.

Care of sick and wounded and supply of arms and equipment stand further removed from troop use than subsistence, having only weak and indirect influence on combat through their results.

Though rarely significant for theory, maintenance factors like hospital location or ammunition depot placement can become decisive in particular strategic decisions, a fact not to be overlooked.

Theory of conduct of war concerns itself with general principles rather than particular cases where maintenance might be decisive, so maintenance theory need not achieve the importance of subsistence theory.

All activities in war logically divide into two classes: those that are 'preparations for war' and 'war itself,' a division that must be reflected in theory.

Preparation requires knowledge of creation, discipline, and maintenance of forces—including artillery, fortification, organization—while conduct of war requires only knowledge of the principal results of prepared means.

The theory of conduct of war occupies itself only with using prepared means for war's object, treating preparation activities' results as given rather than analyzing preparation itself.

The theory presented treats combat as the real contest while treating marches, camps, and cantonments as circumstances more or less identical with it, and subsistence as a given circumstance influencing results.

Both tactics and strategy connect with marches, camps, and cantonments only through combat, with these circumstances being tactical or strategic depending on whether they relate to combat form or significance.

Though separating tactics and strategy may seem pedantic since it has no direct effect on battlefield conduct, it is essential for clearing up confused conceptions and enabling rigorous theoretical progress.

Distinguishing tactics and strategy ensures that author and reader share the same point of view and understand the nature and mutual relations of these essentially different but mutually permeating activities.

Without proper theoretical distinctions, military theory devolves into confused, perplexing ideas resting on no fixed point of view and leading to unsatisfactory, dull, fantastic, and vague results.