Classic Works

C.E. Callwell, Small Wars: Their Principles and Practice (1896)

The roots of modern counterinsurgency strategy are deep. As far back as Roman times historians like Tacitus recorded accounts of regular forces battling local guerrillas, and from these origins a long tradition of studying these peculiar types of conflicts was born. One of the most historically significant efforts to encapsulate lessons from irregular wars, or “small wars,” comes from the pen of British officer C. E. Callwell. When the British Empire of the 19th century stretched across the globe, Callwell gained first-hand experience fighting insurgencies on two continents. He went on to chronicle lessons from those experiences, as each offered multiple opportunities to consider and reconsider how best to wage counterinsurgencies. Today the term “small war” has taken on a broader definition, but it was Caldwell’s exploration of this type of warfare that yielded what remains one of the most insightful treatments of insurgency and counterinsurgency. While his work is a far cry from modern population-centric visions of counterinsurgency, it represents an important starting point in the development of modern counterinsurgency strategy and tactics.

Few of the British strategist’s generation had the combination of experience and scholarly temperament to undertake such an effort. Callwell was a British army officer who served in a series of colonial wars, including the Second Anglo-Afghan War and the First and Second Boer Wars, wrote widely on military and strategic issues (Moreman 2004). While his final postings as a major general during World War I focused on intelligence and logistical issues, he is best known for his studies of counterinsurgency. In summarizing Callwell’s life, one biographer writes that the British officer “was an accomplished linguist, a skilled intelligence officer, and a prolific writer of quality on a wide range of military affairs and on military history throughout his career” (Moreman 2004). These characteristics served him well while examining small wars, though perhaps not in leading troops. Callwell held only one significant command position, during the Second Boer War, in which he was not especially successful. Ultimately, “he was perhaps more accomplished as a theorist than as a soldier,” and while his writings are dated by a particularly patrician view of the non-Western world and an outmoded discussion of logistical issues, his general insights into the nature and strategy of small wars are timeless (Moreman 2004).

This essay aims to outline the major arguments of Callwell’s seminal work Small Wars: Their Principles and Practice, first published in 1896, highlighting those points most relevant to modern strategists and leaving aside outdated tactical issues. It begins by exploring in detail the concept of “small wars” before turning to their characteristics, the central occupation of Callwell’s thinking. The importance of Callwell’s work for later studies of insurgency and irregular wars leads to conclusions about the ongoing relevance of Small Wars for students of strategy and diplomacy. Suffice to say that while the book is well over one hundred years old, it continues to remind modern readers that small wars are characterized both by universal features of war like fog and friction, and by their own special strategic and tactical characteristics, making them especially challenging fights for regular armies of the past, present, and future.

The Concept of Small War

In the opening pages of Small Wars, Callwell admits that the concept of “small wars” is difficult to define, while simultaneously offering an emphatic defense of the term’s importance. It is, after all, the focus of his book. The British officer argues that small wars practically “include all campaigns other than those where both the opposing sides consist of regular troops” (Callwell 1996, 21).[1] He goes on to explain that the term “small war” really has no connection with the scale of a conflict – there may be very larger small wars and very small regular wars (Callwell 1996, 21). Unlike other more conventional types of military conflict, small wars feature diverse conditions, novel types of fighting, and distant theaters of operation which make carrying them out fundamentally different from regular wars and enhance the importance of adapting to circumstances (Callwell 1996, 23). Callwell goes on to argue that conducting small wars is in “certain respects an art by itself, diverging widely from what is adapted to the conditions of regular warfare;” still, he does qualify this statement by suggesting the differences are not so wide that comparisons between the two types of war cannot be made (Callwell 1996, 23).

The British officer offers an additional qualification. He observes that some small wars may be fought against troops featuring at least the “form and organization of regular troops” even though they cannot technically be classified as regular militaries (Callwell 1996, 29). In these cases, “the warfare will somewhat resemble the struggles between modern armies, and the principles of modern strategy and tactics are largely if not wholly applicable” (Callwell 1996, 29). Other alternatives include those cases when the opponent may be disciplined but poorly armed, “fanatical” in their fighting styles, mounted, or consist of various guerilla types (Callwell 1996, 30 – 32). Each of these diverse enemies is ultimately considered in Small Wars one way or another.

To ultimately support his discussion of small wars, Callwell draws on a rich history of cases detailing well known regular, European combatants, especially Great Britain, fighting irregular forces in Central Asia, South Africa, and throughout the Middle East. Given the diverse set of potential adversaries in small wars, the British officer makes one of his most incisive suggestions. He urges his readers to study “the habits, the customs, and the mode of action on the battlefield of the enemy” before fighting and argues that such careful observation should be pursued by all levels of officer so that each is ready to overcome any obstacles resulting from local populations (Callwell 1996, 33). That habits, customs, and battlefield actions might vary so widely that they require careful study, suggests just how diverse the characteristics of small wars may be, as opposed to the relatively uniform wars of regular European armies.

Having established the notion of small wars, Callwell breaks down this particular type of fight into three categories – “campaigns of conquest or annexation, campaigns for the suppression of insurrections or lawlessness or for the settlement of conquered or annexed territory, and campaigns undertaken to wipe out an insult, or avenge a wrong, or to overthrow a dangerous enemy” (Callwell 1996, 25). Campaigns of conquest or annexation are those launched against foreign enemies and fought in their territory (Callwell 1996, 25). These are a type of external or interstate war. The second type, campaigns against insurrections or to settle of occupied territory, are necessarily internal and often follow small wars of the first variety (Callwell 1996, 26). Because irregular opponents in these wars are so fluid, engage harassing tactics, and take place in far off regions, they “are most difficult to bring to a satisfactory conclusion, and are always most trying to the troops” (Callwell 1996, 26). Finally, campaigns to avenge a wrong generally take place abroad, and they may also include “expeditions undertaken for some ulterior political purpose, or to establish order in some foreign land” (Callwell 1996, 27). Callwell adds that these types of campaigns need not necessarily crush an adversary to achieve the political objective in mind, although they may also turn into campaigns of conquest over time (Callwell 1996, 27).

These early chapters on the nature of small war also reveal Callwell’s blatant ethnocentrism. The derogatory term “savage” and many like it are often used by the British colonial officer to describe native irregular opponents of regular forces around the world. In line with many of his day, Callwell’s belief in the superiority of European peoples infuses Small Wars. Unfortunately, Callwell’s insistence on using pejorative terms for non-European force may have the result of turning modern readers away from his work without appreciating some of the lasting implications of his study. Ultimately, modern students of strategy and diplomacy should keep Callwell’s writings in the context of the author’s time while examining them for lasting insights about military action.

Setting Military Objectives

Aside from defining the term “small war,” Callwell spends significant time in the earliest pages of his book focused on the importance of establishing sound military objectives. To this end, Callwell argues that the objective of a small war will be a function of “the circumstances which have led up to the campaign” (Callwell 1996, 34). Wars do not spring from the ether; rather, they are the result of some political process that has undergone a transformation into contests of military prowess. The British officer stresses that “the advantage of having a well-defined objective even for a time can, however, scarcely be over-rated” (Callwell 1996, 37). An objective keeps military action focused, and if it helps guide military action, the likelihood of success in war is enhanced. So what determines the objective? Callwell highlights several potential considerations.

In cases where the enemy has a centralized government, the fall of their capital may be a fine military objective (Callwell 1996, 35). Such a military objective is uncommon, however, since capitals in “the theaters of small war are rarely of the same importance” as in fully developed, modern states (Callwell 1996, 35). In other instances, the aim may be to “overthrow a dangerous military power,” and in turn “the objective is the army of the enemy wherever it may be” (Callwell 1996, 39). In this view, the fight must be taken directly to the military forces of the opponent. If the enemy force cannot be directly targeted, an alternative, perhaps some prestigious location the opponent values, may be threatened in an effort to draw an irregular enemy out to fight (Callwell 1996, 39). Indeed, regular troops will always want a pitched battle, it is the kind of fight in which superior equipment and training will pay dividends (Callwell 1996, 39). Still, this type of fight is not always achievable in small wars.

When there is not a king, capital, army, stronghold, or population center to make the military objective, picking one can be difficult. In these cases, the regular force must focus on taking what its enemy most prizes, and this may take many different forms, including raiding livestock or destroying crops, provided that these shock and humiliate the irregular opponent into a stand-up fight (Callwell 1996, 40). Finally, there are objectives in wars meant to quell insurrections. In these fights, the “object is not only to prove to the opposing force unmistakably which is stronger, but also to inflict punishment on those who have taken up arms” (Callwell 1996, 41). Inflicting high casualties on the enemy may be most desirable in these cases. Still, there are limits, and a blend of firmness and clemency may be best since the ultimate aim is a better peace (Callwell 1996, 41). An objective that is “overawing” rather than just “the exasperation of the enemy” is the end to ultimately keep in mind (Callwell 1996, 42). Ultimately, Callwell’s stress on the importance of setting objectives is a reminder of lasting importance.

Special Features of Small Wars

Perhaps the most important insight of Small Wars focuses on the relationship between strategy and tactics in irregular wars. In short, Callwell argues that in these particular types of armed conflict, “tactics favour the regular army while strategy favours the enemy” and consequently, the object for a regular force “is to fight, not to manoeuver” (Callwell 1996, 85). The British officer details the logic of this argument. First, regular militaries are hampered strategically in small wars because their organization, supply system, and advanced armament, which are sources of power in regular wars, hinder flexible and rapid movement (Callwell 1996, 85). Guerrilla troops face none of these challenges. They rely on no fixed bases or supply systems, operate in their own country, and may move in and disburse into small groups even after a military defeat, all of which leaves an irregular enemy “untrammeled by the shackles which so limit the regular army’s liberty of action, a fact which is of great strategical importance” (Callwell 1996, 86). The regular army is strategically stuck while the irregular force is strategically fluid.

There is the related issue of communications, a consideration which Callwell examines in some detail. Defense of modern communications systems, essential to supply and medical support, ties up large numbers of regular troops and further slows strategic movement on the part of regular troops fighting irregular wars (Callwell 1996, 85). Wounded likewise fix a regular force in place. Callwell notes that the rules for handling wounded are complicated in small wars since the enemy cannot be trusted to treat them well; thus, wounded require additional communications and logistical support that consequently hinder regular army mobility (Callwell 1996, 95 – 96). Indeed, in many matters of supply and command the regular army relies on communications that can be cut while they cannot in turn cut irregular communications (Callwell 1996, 86 – 87). Irregulars have minimal communications requirements and so they may speedily move without fear of abandoning communications nodes. In all these ways the strategic advantage is born – an irregular force may melt away and quickly reconstitute as needed while the regular force must carry significant equipment, defend supply routes, secure the wounded, and guard lines of communication (Callwell 1996, 87- 88).

This is not the end of the story. Callwell makes clear that “strategy is not, however, the final arbiter in war” (Callwell 1996, 90). Instead, “the battlefield decides” the fate of an armed conflict and it is here that regular forces enjoy decided advantage (Callwell 1996, 90). Slow though they may be strategically, once a struggle comes to blows, regular forces generally have superior weapons, discipline, training, organization, and esprit de corps than their irregular opponents, making the conventional army a far more formidable fighting force once on the battlefield (Callwell 1996, 90). Because of this mismatch, Callwell implores his readers that “the object is to fight, not to manoeuvre” so that the tactical advantage of regular forces may be brought to bear (Callwell 1996, 91). To those who might still argue in favor of maneuvering for a stunning win, Callwell reminds that that unforeseen challenges will always arise and cause great risk given the limitations placed on regular troops – it is better to fight when you can (Callwell 1996, 93).

Yet, as Callwell is wary of law-like pronouncements in the conduct of war, even this seemingly clear directive has caveats. Given the uncertainty naturally wrapped up in war, there are no fixed instructions or theories of victory. According to Callwell there may indeed be circumstances, for example when the enemy has a strong defensive position, where it is better to hold off from fighting (Callwell 1996, 94). Even the strongest regular forces might find defeat on the battlefield if they are forced to fight under especially unfavorable circumstances. It is certainly better to wait for a more opportune moment to fight than to force the issue on unfavorable ground.

As a rule, however, Small Wars focuses on the importance of bringing irregular forces to battle and aiming for their decisive defeat. Callwell hammers his larger point home:

Battles, then, are the objects to be sought for by the regular troops, and since the enemy as a general rule shirks engagement in the open field, the strongest grounds exist for tempting him to fight, for drawing him on by skillful dispositions, and for inducing him to enter eagerly upon the conflict if he shows symptoms of inclination for a battle. Where it is so difficult to bring matters to a tactical issue, it is clear that when efforts in this direction prove successful the fight should be decisive (Callwell 1996, 106).

Following similar logic, the British officer cautions that regular troops ought to avoid desultory warfare, meaning scattered engagements, during small wars. This type of fighting takes place in environments not suited to regular troops and bleeds their readiness over time, not just through slow, steady losses, but also from disease and persistent resupply problems associated with this kind of fighting (Callwell 1996, 97 – 98). Additionally, desultory warfare gives the irregular enemy time to organize and launch into guerilla warfare, “the most unfavourable shape which a campaign can take for the regular troops” (Callwell 1996, 97 – 100). Even seemingly benign forms of desultory warfare, including skirmishes, should be avoided since they do not play into the strengths of regular troops (Callwell 1996, 102). Perhaps most insidious, indecision on the part of a commander during a small war often causes the fight to slip into desultory war (Callwell 1996, 100). The only way to avoid desultory warfare is to force battle on the enemy, and if a military leader fails to appreciate this fact, he or she does their cause a great disservice since the irregular force will drive the conflict toward desultory war (Callwell 1996, 97).

Callwell also considers the effects of dividing regular forces during a small war and the influence this may have on achieving a decisive victory on the battlefield. He acknowledges that splitting the main body of a force up is generally bad strategy because an enemy need only defeat each smaller force in succession to achieve victory (Callwell 1996, 108). This rule is “far from absolute,” however, and as long as each subdivision of the force is strong enough to defend itself from the any projected enemy, there may be good reasons for splitting the force (Callwell 1996, 108). Indeed, during a small war there may be instances when dividing the main force is precisely the best course of action, for example when targeting multiple objectives, aiming to intimidate over large swaths of territory, attempting to confuse opponents, and striving to generate multiple opportunities for success (Callwell 1996, 108 – 111).

One specific reason a force might choose to divide is in an effort to protect lines of communication. As discussed earlier, securing communications can stress forces, especially as they cover large portions of ground in semi-settled terrain; yet, there are also circumstances when such protection is unneeded, such as when a unit becomes a flying column, a special type of troop arrangement discussed later in this essay (Callwell 1996, 115 – 119). This is certainly a special case though. Callwell reminds his readers that “an army without communications in a hostile country, which meets with a reverse, is in a very serious plight” since there is no way to signal for support or talk with other units or command (Callwell 1996, 122 – 123). Going without communications is a serious matter. If a detachment of troops chooses to pursue this route, wanting to maximize its flexibility and speed, they should not be disconnected for long periods of time, and forces engaged in this activity should be specially organized and equipped to handle these types of operations (Callwell 1996, 124).

Splitting the force and going without communications as a flying column are just two ways that a commander in small wars may attempt to engage in the kinds of bold operations Callwell ultimately applauds. He maintains throughout the book the importance of boldly seizing and maintaining the initiative not just in irregular wars, but in all war (Callwell 1996, 71). The initiative is essentially placing one’s forces in a position that requires his opponent to react. Callwell argues that “to dominate the course of operation, to hold the lead and compel the antagonist to follow suit, is the way to achieve the victory” (Callwell 1996, 71). The author of Small Wars contends that the political conditions leading up to a small war naturally compel regular forces to act first (Callwell 1996, 71). Irregular forces will generally avoid the offensive, choosing instead to take advantage of their local knowledge to fashion viable defensive positions, so regular troops are generally handed an opportunity to employ the offensive and carry the initiative (Callwell 1996, 150). Additionally, the regular force engaged in a small war can take the initiative early because there is no race to mobilize like in a regular war (Callwell 1996, 72). It then falls on regular troops to maintain the initiative that is often ceded to them at the start of a small war.

A “resolute bearing” and “determined course of action,” often hallmarks of regular forces, can go a long way in cultivating the initiative; however; even with these, Callwell stresses that “it is essential that the campaign should not be commenced till there are sufficient forces on the spot to prosecute the work with vigor, and till these are thoroughly organized and equipped for the task which they have in hand, whatever it may be” (Callwell 1996, 73). If small wars are started without enough strength in the regular force, the subsequent delay in collecting that strength may allow the irregular enemy to organize, and the enemy will be fast to take advantage of this window (Callwell 1996, 74). Likewise, prompt attack with sufficient forces may be enough to end a small work quickly at the very start (Callwell 1996, 74). To maintain the initiative, the strategic offense must always be in the minds of regular forces even if there are moments when the tactical defensive may be employed (Callwell 1996, 75 – 76). On this point Callwell makes several forceful statements.

First, “the regular army must force its way into the enemy’s country and seek him out” (Callwell 1996, 75). Additionally, the regular force must be ready to fight its opponent “wherever he may be found” and “play to win and not for safety” (Callwell 1996, 75). After all, “it is not a question of merely maintaining the initiative, but of compelling the enemy to see at every turn that he has lost it” (Callwell 1996, 75). Callwell argues that “the enemy must not only be beaten” but “he must be beaten thoroughly” (Callwell 1996, 151). The initiative is a means to an end, and by pushing the irregular opponent onto his heels, the regular force stands the greatest chance for success. While this is generally an aim during war, a difference between regular and irregular war is that the guerilla forces “swell and contract according to the moral effect which is produced” (Callwell 1996, 76). In other words, if success after success is met on a battlefield that chases down the irregular forces, not only will they be degraded in fighting, but they will be denied any new recruits. Success thanks to bold action should be followed up since “in small wars a single blow will often achieve important results, but a succession of blows paralyses the enemy” (Callwell 1996, 79 – 80).

In the end, “vigour and decision are at the root of effective conduct of [small wars]” (Callwell 1996, 84). One cannot just drive the enemy from the battlefield and take valuable positions as in 19th century European wars; rather, “what is wanted is a big casualty list in the hostile ranks – they have been brought up to the scratch of accepting battle, they must feel what battle against a disciplined army means” (Callwell 1996, 152). Such an aim warrants even attacking an irregular opponent when he is in retreat (Callwell 1996, 152). And while it may seem distasteful or dishonorable, from Callwell’s point of view, such actions will ultimately lead to less bloodshed and a quicker termination to the violence.

It is not just the nature of the attack that is different in small wars, but a host of other differences manifest themselves, especially when these types of fights devolve into guerilla warfare. The pages of Small Wars make clear repeatedly that this type of fighting ought to be avoided, especially since it prevents the pitched engagements in which the tactical strengths of regular forces might be employed (Callwell 1996, 125). Not only is it difficult to draw the enemy out in these kinds of fights, but “guerilla warfare is what the regular armies always have most to dread, and when this is directed by a leader with a genius for war, an effective campaign becomes well-nigh impossible” (Callwell 1996, 126). Still, Callwell accepts that at some point during small wars guerilla operations are likely; thus, there is a special need to address this type of combat (Callwell 1996, 127).

He begins by exploring the type of terrain that suits itself to guerilla tactics and highlights hills, broken ground, and jungles as especially conducive to irregular fighters (Callwell 1996, 127). Meanwhile, prairies, veld, or steppes are poor locations for guerilla operations, though they are suitable for mounted units whose strength comes from rapid movement rather than ability to conceal (Callwell 1996, 127). With these physical considerations established, Callwell moves on to examine other features of guerilla operations. Foremost among these are hit-and-run tactics employing surprises and speed (Callwell 1996, 127). While surprise is challenging for a large regular force to achieve, small irregular forces find it a vital ally. To be certain, the British officer does not suggest that the dangers from surprise cannot be mitigated, but rather that surprise is often the realm of the insurgent, and the regular force can only hope to follow up surprise attacks by having troops on standby to pursue the attackers (Callwell 1996, 127). If a small war drifts into a place where ambushes and small surprise attacks are commonplace for extended periods of time, this is often the fault of the regular troops for not holding the initiative, bringing the fight to the enemy, and pursuing a quick conclusion to hostilities (Callwell 1996, 129).

While “vigourous leadership” and the “rapid movement of columns” are important to the success of regular troops in a small war, these are not enough (Callwell 1996, 130). Instead, a “strategical organization” of territory is most important, an organization that facilitates “constantly harassing the enemy and of giving the hostile detachments no rest” (Callwell 1996, 130). This organization is rooted in defining the theater of operations. Callwell argues that “the whole area of operations should be sub-divided into sections, each of which has its own military force or aggregate of military detachments told off to it” (Callwell 1996, 130). This organization helps pressure irregular forces in multiple locations at once provided each subdivision has its own defensive outposts, secure blockhouses, supply chains, and mobile columns (Callwell 1996, 131). Additionally, each of these sectors should be defined in such a way that they may be methodically cleared of supplies that may be useful to insurgent groups (Callwell 1996, 131). There is no proper rule for the size of the divisions of territory, but they may be generally larger in open spaces and smaller in hilly or brush filled regions (Callwell 1996, 134).

“The sub-division of the theatre of war into sections, each with its commander, its chains of posts, and its mobile columns may be said to be the first step toward dealing with guerilla warfare effectively,” writes Callwell (Callwell 1996, 133). Troops may need to flow from sub-division to sub-division depending on where insurgents are pushed and as some divisions of territory become unsuitable for their operations. Posts should be set up in each subdivision to hold the territory, and if they are well made, they only need a few troops to defend (Callwell 1996, 134). This organization of territories and defensive positions facilitates Callwell’s most essential feature of counterinsurgency warfare – mobile columns. He argues that “the essence of operations against guerillas is to be found in utilizing the troops available as far as possible for mobile columns” while garrisons and defensive positions should soak up only as many troops as needed to ensure defensibility (Callwell 1996, 134). A special type mobile troop arrangement, called a flying column, is at the heart of pressuring insurgents. By drawing on a rich history of these columns, especially their use in Afghanistan, Burma, South Africa, and the western United States, Callwell constructs the ideal arrangement for fighting against guerillas (Callwell 1996, 135).

First, flying columns must be equipped to travel light, since mobility is the most important feature of their activities, and men comprising them should be accustomed to “fatigue and hardships” and thus be kept in good condition (Callwell 1996, 136). Flying columns must be able to survive on their own for some time as they generally do not enjoy communications back to headquarters or the main body of regular forces. Next, “… columns should be as small as possible consistent with safety” and must be flexible in their makeup – mounted troops for plains and bush infantry for jungle environments (Callwell 1996, 136). If the environment is favorable for mounted units, flying columns made of these troops are capable of achieving surprise and “sweeping the booty in from over a wide area” if this end is deemed valuable to winning a war (Callwell 1996, 137). Maximizing mobility, which is in part a function of a unit’s size, is a central aim of flying columns, and the value of swift, unrestricted mobility was well established by the British experience fighting Boers in South Africa (Callwell 1996, 140). Callwell writes:

The smaller the column the more mobile it will generally be; the more mobile it is the more suddenly it can deliver its strokes; and the essence of combating guerilla warfare is to hit unexpectedly and hard. The enemy’s game likewise it to hit unexpectedly, but generally not very hard… (Callwell 1996, 141).

Finally, flying columns must also be independent within their area of operations, that is to say, commanders should be given directives but have the freedom to change course as needed; this helps deal with the difficulty of controlling many columns over a large territory (Callwell 1996, 142). Such a devolved form of command demands self-reliant subordinate officers, but is the only way to make flying columns work over large distances (Callwell 1996, 143).

Beyond the importance of initiative, geographic organization, and flying columns, Callwell admits that when faced with guerilla methods, regular troops by necessity must resort frequently to punitive measures directed against the possession of their antagonists” (Callwell 1996, 145). For example, cattle may be carried off and property destroyed, provided such actions are designed to force a battle in which regular troops will hold the tactical advantage (Callwell 1996, 145). While destroying depots of food or ammunition are clearly morally defensible, Callwell defends the more general practice of raiding, which some might see it as contrary to the “true spirt of waging war” (Callwell 1996, 146). Such practices, when aimed at ending a war, are far preferable to the alternative of prolonged, costly, and unsuccessful desultory war. He goes on to argue that when aiming to pacify a region, “the enemy must be chastised up to a certain point but should not be driven to desperation” (Callwell 1996, 147 – 148). Resolve and force may be needed, but they should not blind a commander to the ultimate political objective. Indeed, “wholesale destruction of the property of the enemy may sometimes do more harm than good” when the political objective of the war is taken into account (Callwell 1996, 149).

Two activities, collection and intelligence, and achievement of surprise, may go a long way in helping win a small war and stopping it from sliding into a long and unnecessarily destructive conflict. Intelligence is made of at least two parts according to Callwell – knowledge of local geography and understanding of an enemy’s disposition, fighting qualities, and strength (Callwell 1996, 43 – 44). Such information is much more difficult to gather during small wars than regular wars; consequently, small wars are often carried out with relatively little information (Callwell 1996, 43). The reasons for difficulties are timeless – small wars way begin unexpectedly, are situated far from home in foreign regions without extensive mapping, and irregular opponents can more easily mask their strength, weapons, and fighting capabilities (Callwell 1996, 43). Friction, the uncertainty of war that makes even the simplest tasks difficult, is only enhanced when geography is unknown and the enemy poorly understood (Callwell 1996, 62- 63). And the intelligence on these items that may be on hand can easily be defective (Callwell 1996, 47). Consequently, communications may be slowed, resupply hindered, pursuit of the guerilla fighters inhibited, and military disaster courted (Callwell 1996, 45). Perhaps most unfortunate, poor intelligence may hobble a commander, cause him to delay, and in turn drag out a small war into desultory fighting (Callwell 1996, 47).

The causes of uncertainty in intelligence during irregular war differ from those of regular war even though the commander’s need to interpret reconnaissance, information from spies, and circumstantial evidence remain the same (Callwell 1996, 51). In regular war, armies follow certain tendencies, like using screens of outposts or controlling media, to hide their strength or capabilities, but these fall away once armies face one another on a field of battle and relative power can be more clearly assessed; however, in small wars, “the more irregular and less organized the forces of the enemy are, the more independent do they become from the strategical rules” (Callwell 1996, 52). For example, the enemy may disburse after a defeat and hide aspects of its nature even during combat; moreover, it will move quickly and strike swiftly in ways a regular army cannot, only adding to the uncertainty a regular army faces (Callwell 1996, 52).

While regular armies fighting in small wars may suffer from lack of intelligence about their foe, irregular forces enjoy several information advantages, including knowing the territory in which they fight, the capabilities of regular troops, and the movements of modern armies with some consistency (Callwell 1996, 53 – 54). Locals need only pay attention to the regular army as it traverses the countryside and listen to its men as they swap gossip to know much of value to insurgent forces (Callwell 1996, 54). Guerillas are at a decided advantage, but Callwell suggests this informal network of gathering information may be turned against an irregular opponent by intentionally spreading false information that lures them into traps (Callwell 1996, 54 – 55). Ultimately, the individual circumstances of a particular conflict will greatly affect acquiring intelligence or preventing the enemy from gathering it, but in the best of circumstances a regular force must expect to face intelligence shortfall and difficulties (Callwell 1996, 56).

On the issue of surprise, Callwell makes a clear link to intelligence operations. He argues that “in no class of warfare is a well-organized and well served intelligence department more essential than in that against guerillas… Guerillas trust to secret and to sudden strokes, and if the secret is discovered their plan miscarries” (Callwell 1996, 143). Intelligence, in short, may break up the activities of insurgents. Counterintelligence is no less important if regular forces are themselves to achieve surprise. “On the other hand,” writes Callwell, “all movements intended against [irregular forces] must be concealed or they will be scared away” (Callwell 1996, 143). Both the collection of intelligence to prevent surprise from the enemy, and the preservation of information to achieve surprise against the enemy, “call for a very efficient and watchful secret service, for a trustworthy corps of spies and for a wide awake police, with a capable intelligence department controlling the whole” (Callwell 1996, 143 – 144). Additionally, scouts from among the loyal native population can be helpful in supplementing intelligence activities, especially when it comes to surveying local terrain and geography (Callwell 1996, 144).

If secrets can be kept, it is possible for regular troops to lure out irregulars into unfavorable situations (Callwell 1996, 227). Because irregular troops see the nature of regular troops as slow, predictable, and routine, “they come to underrate the capacity of their antagonists for turning the tables upon them and for employing stratagem and artifice upon their side” (Callwell 1996, 227 – 228). For example, regular troops in retreat might appear a good target for guerrillas; however, a sly commander can see this as an opportunity to trap, engage, and kill many insurgents (Callwell 1996, 228). Additionally, “although in small wars the enemy is generally well fitted by nature and temperament for devising ambuscades and carrying out surprises, it is by no means so difficult to put this method of warfare in force against him as might be supposed” (Callwell 1996, 240). Rapid marches, mobility, secret military objectives, and distractions may all be used to help achieve surprise (Callwell 1996, 241 – 244). These may also be used to facilitate laying traps and ambushes. Still, it is not always possible to draw out the enemy, and regular troops must be prepared to find alternative ways of bringing about a stand-up fight (Callwell 1996, 236 – 238).

In the end, small wars are a special class of war for C.E. Callwell. They share the essential features with other types of violent armed conflict, but they are defined by their own grammar, a grammar that affects the regular and irregular participants in such a fight differently. The regular forces, with supreme weapons and training, enjoy the tactical advantage and thus seek fights. This may be achieved through soundly organizing the theater of war and creatively employing flying columns. However, the insurgents, holding superior local knowledge and intelligence, are capable of blending back into the population. They practice speedy mobility, hope to drag out a small war to turn it into a guerilla affair, and slowly bleed their opponents over time. This asymmetry is atypical for contests between two regular opponents, but it is the defining characteristic of small wars, according to Callwell.

Callwell’s Influence

Small Wars holds an important place in the larger counterinsurgency literature. The book, published originally in 1896, was one of the earliest systematic studies of irregular warfare by a European military officer and scholar. Consequently, it became a reference point for later works that sought to confirm, refute, or borrow from its findings. For example, during the period of the American intervention in the Dominican Republic during the early 20th century, many Marines, some of which would go on to write the Marine Corps Small Wars Manual, were routinely citing “the British campaigns in Kashmir and South Africa,” while the Marine Corps Gazette was publishing thoughtful authors who “seem to have read the 1906 edition of C.E. Callwell’s famous Small Wars doctrinal manual” (Bickel 2001, 133). Likewise, following American operations in Nicaragua, American Harold Utley set out to capture the tactics and techniques for fighting small wars; in so doing, he liberally referred back to Callwell, for instance borrowing the British officer’s definition for the term “small war” itself (Bickel 2001, 183).

Other Americans like Merritt Edson, whose work would influence the development of the Marine Corps Small Wars Manual, also seemed to sample Callwell even if they did not cite the earlier work directly (Bickel 2001, 216). The 1935 publication Small Wars Operations, the earlier title of what would become the Manual, used historical examples to buttress its claims in much the same way as Callwell, only further suggesting the influence of the older book (Bickel 2001, 242). This influence survived revisions and remains in the 1940 edition of the Manual (Bickel 2001, 242). It seems clear that the ideas in Small Wars had some level of importance in the development of what became the most fully realized U.S. military volume on the conduct of irregular operations until the 21st century. Still, “one should not overstate Callwell’s influence on Marine doctrine” since aside from his concept of using blockhouses in the field, Callwell likely offered more methodological inspiration and an independent confirmation of ideas Marines were already developing while fighting throughout Central America (Bickel 2001, 242).

Since the time Callwell penned his book, many updated visions for counterinsurgency warfare have sprung up to take their place on library bookshelves around the world. Today one of the most widely read is David Galula’s Counterinsurgency Warfare: Theory and Practice. It outlines a different vision for how regular forces might fight against insurgents. Rather than bringing the battle to guerillas, as argued by Callwell, Galula advocates securing the populations of regions afflicted by irregular warfare. Galula lays the groundwork for the modern concept of population-centric warfare in which the objective of the regular force is the population itself rather than the enemy directly (Galula, 4 – 5). While this approach is certainly not a natural extension of Callwell’s central advice, to divorce it from the early small wars scholarship is a mistake. To appreciate the development of books like Galula’s requires a careful reading of the past, and it is here that Callwell might offer the greatest value. Galula and Callwell, both careful observers of insurgencies, may have come to some different conclusions about strategy and even tactics, but they largely agree on the difficulties associated with these particular kinds of fights. On the challenges of intelligence collection, mobility, training, and a host of other issues, the two men, whose major works are separated by over half a century, largely agree. The process of learning to fight against insurgencies is just that, a process, and modern students would do well to remember the origins of today’s strategic thinking.

Perhaps the most lasting legacy of Callwell’s book, however, is the term “small wars.” Indeed, today one of the leading sources for information about the conduct of irregular warfare is the Small Wars Journal. To be sure, Callwell did not make up this term himself. It was in common usage throughout the British army during the time in which he was writing. However, his description of small wars, the difficulties they pose regular forces, and the specific features that make them up, have stood the test of time. To appreciate the contemporary use of the concept requires a careful consideration of Callwell’s book and his development of the term for practical application. Some of what Callwell has to say is out of date, but his book still captures the essence of these challenging conflicts. Even more importantly, his book serves in many ways as a baseline for understanding where counterinsurgency strategy was in the past, and for appreciating the differences between this baseline and contemporary developments.



[1] Callwell’s definition of “small wars” is not the only one. Another popular definition is taken from the Marine Corps Small Wars Manual of 1940. That document defines them as “operations undertaken under executive authority, wherein military force is combined with diplomatic pressure in the internal or external affairs of another state whose government is unstable, inadequate, or unsatisfactory for the preservation of life and of such interests as are determined by foreign policy of our Nation” (Marine Corps, 1-1). Today, the term “small war” is also often used as a synonym for counterinsurgency.


Bibliography: Writings Relating to Small Wars

Bickel, Keith B. Mars Learning: The Marine Corps’ Development of Small Wars Doctrine, 1915-1940. Boulder, CO: Westview Press, 2001.

Bickel’s book, based on his dissertation which is cited in this paper, is the definitive account of how the ideas captured in the Marine Corps Small Wars Manual were hard won over twenty-five years. Indeed, his work is the best for understanding the context and the authors that helped give rise to the Manual.

Boot, Max. The Savage Wars of Peace: Small Wars and the Rise of American Power. New York, NY: Basic Books, 2014.

By reviewing instances of American involvement in small wars from throughout the 19th and 20th centuries, Boot highlights just how long the United States has been fighting and learning from these wars. He devotes an entire chapter to the Small Wars Manual that is especially useful in putting it into context.

Caldwell, C. E. Small Wars: Their Principles and Practice. Lincoln, NE:  University of Nebraska Press, 1996.

Col. Caldwell’s book reflects the lessons British officers took from the colonial wars in the 19th century. A bit dated at points, it remains a classic for understanding the development of small war or counterinsurgency thinking. Indeed, many of the key concepts and terms used by later writers are rooted in those coined by Caldwell.

Corps, United States Marine. Small Wars Manual. Washington, DC: GPO, 1940.

The Small Wars Manual captures many of the timeless strategic and tactical aspects of fighting insurgencies and remains especially valuable today as a historical document capturing how the U.S. military, and the Marine Corps in particular, learned from past small wars and institutionalized these lessons.

Galula, David. Counterinsurgency Warfare: Theory and Practice. Westport, CT: Praeger, 2006.

This may be the seminal work on counterinsurgency published in the 20th century, and Galula is a required reading for both scholars and practitioners alike. Born of his experiences in fighting insurgencies in Asia and North Africa, this book captures many of the most widely accepted tenants of counterinsurgency in just one hundred pages.

Gentile, Gian P. Wrong Turn: America’s Deadly Embrace of Counterinsurgency. New York, NY: The New Press, 2013.

Perhaps the leading proponent of an alternative view toward counterinsurgency practices, Col. Gian Gentile suggests much that we take as given about population centric counterinsurgency operations is often irrelevant and may be problematic for attaining American policy objectives. This book represents the summation of Gentile’s observations in Iraq and Afghanistan and is the culmination of several earlier works that began developing his central ideas.

Kilcullen, David. The Accidental Guerrilla: Fighting Small Wars in the Midst of a Big One. New York, NY: Oxford University Press, 2009.

One of several books on the subject of counterinsurgency written by long-time practitioner and General Petraeus advisor David Kilcullen, The Accidental Guerrilla now graces many a syllabus on in war colleges and strategy seminars. In it, he argues that what might be considered modern small wars cannot be addressed using counterterrorism and counterinsurgency strategies of the past, but need new strategies that address singular aspects of these fights. His nuanced analysis of the situations in Iraq and Afghanistan are especially thought provoking.

T. R. Moreman. ‘Callwell, Sir Charles Edward (1859–1928).’ Oxford Dictionary of National Biography. Oxford, UK: Oxford University Press, 2004; online edn, Jan 2008 [, accessed 16 Feb 2016]

Moreman offers a succinct overview of Callwell’s life imminently suitable for an introduction to the man and the events that shaped his thinking. A quick read, this is the first place a student of strategy and diplomacy should turn for an accurate and brief discussion of Callwell.

Nagl, John A. Learning to Eat Soup with a Knife: Counterinsurgency Lessons from Malaya and Vietnam. University of Chicago Press, 2009.

John Nagl, one of the authors of The US Army/Marine Corps Counterinsurgency Field Manual, offers his take on the experiences of counterinsurgency in Malaya and Vietnam in a book that has become required reading for students of counterinsurgency. He explores how military organizations learn during counterinsurgency operations and alter their methods over time.

Nagl, John A., James F. Amos, Sarah Sewall, and David H. Petraeus. The US Army/Marine Corps Counterinsurgency Field Manual. No. 3-24. University of Chicago Press, 2008.

This is the latest work on counterinsurgency by the U.S. military and is widely credited with being central to the improved effectiveness of American military units operating in Iraq and Afghanistan in the early 21st century. Because it is the latest manifestation of American military thinking on how to fight counterinsurgencies, it is required reading for any student seriously interested in the subject.