The Myth of Successful Defensive Lines

Throughout history nations have made considerable efforts to find solutions to defend themselves against external threats. Perhaps the best example would be the creation of vast and expensive defensive lines to protect their countries from invasion or infiltration. Yet despite the considerable time and resources that have been expended into such endeavors nearly all without exception have inevitably failed to accomplish their ultimate goals. Defensive lines throughout history have typically failed to safeguard countries from external aggression.

If we look at defensive lines in military history they typically fall into two categories; those designed to stop conventional attacks by an invading army, and those designed to stop insurgents, bandits, or terrorists, from infiltrating sovereign territory. In the case of the former they have almost always failed to protect their respective countries while in the latter their success is often limited to the short term. Obviously the first thing to consider is how defensive lines are supposed to work.

Firstly, it should be noted that defensive lines are an inherently passive means to protect a country. They are designed as a physical means to prevent an enemy from invading or violating a very specific geographic location. The supposed logic behind their construction is that either the enemy would try outflanking the defensive line, thus allowing the defender to concentrate his forces against the attacking force, or the aggressor will be forced to attack the defensive line and play right into the defender’s hand. While this seems self evident and simple in theory, few things in military theory translate smoothly into practice.

In the case of constructing defensive lines in counter-terrorism and counter-insurgency the primary focus is decreasing terrorism from external forces in the former and limiting aid to insurgents already inside friendly territory in the latter.

While no expert would challenge the assertion that a defensive line can protect vital territory and offer the defender some degree of strategic options it is usually the case that elaborate defensive lines inevitably lead to a defensive attitude. And herein lies the quintessential flaw of defensive lines; they promote passiveness, intentionally or not, and concede initiative to the enemy. Perhaps the best example of this would be the “Maginot mentality” that afflicted the French army during the “Second World War.” The French, who had suffered six million casualties during “World War One,” constructed the Maginot line to deter another German invasion. However, despite being one of the great engineering marvels of the 20th century, the German air force flew over it and the German army outflanked it by going through the supposedly impenetrable Ardennes forests. While it took more than six years to build the Maginot line, it only took the Germans six weeks to conquer France.

Perhaps, and as absurd as it sounds, the majority of times defensive lines have failed is when they are simply outflanked and the defenders (having a mostly passive disposition) are unable to react effectively. Some of the time the defenders had built a defensive line to a certain length and then relied on supposedly impassable terrain, neutral borders, or sheer distance to do the rest. There are too many examples to cite but obvious ones include the aforementioned Maginot line, the Metaxas line in Greece, the French border fortifications before the “First World War,” and the Saddam Line.

Regarding the Metaxas line the Greeks built it to protect against a Bulgarian invasion, but when the Germans invaded Greece in 1941 they outflanked it by going through Yugoslavia. The Franco-German border fortifications prior to 1914 were likewise rendered redundant by the “Schlieffen plan” that by passed them by going through neutral Belgium at the start of the “First World War.” As the for the Saddam line the Iraqi forces simply thought that coalition forces would get lost in the desert as they had before them. Unfortunately for the Iraqis the advent of GPS made the task of outflanking the Saddam line child’s play.

Even defensive lines that cannot be outflanked, and are manned by competent soldiers can be defeated. In these situations it is usually a case of the attacker concentrating enough numbers and firepower and breaching part of the line. While this often results in disproportionate casualties for the attacker, a successful breach usually renders the whole line useless as the rest of it is then open to being bypassed or flanked. This highlights perhaps the biggest liability of defensive lines; they are inherently passive and are only effective at the points at which they are attacked. While perhaps the best that can be hoped from defensive lines is that they provide a trip wire to slow enemy forces to allow the defender to concentrate their reserves for a counter attack, all too often they are expected to halt the enemy almost exclusively by themselves.

Perhaps the best example occurred during “World War 1”, arguably the conflict most associated with the power of the defense, when the Germans relied upon the “Siegfried line” to protect their occupation of north eastern France. While it certainly withstood many assaults it was breached twice relatively easily by well executed British attacks in 1917 and 1918. During the former the British were unable to exploit the breach due to a lack of sufficient reserves, but in the latter the successful breach unhinged the whole line and the Germans were pushed back and forced to accept a humiliating armistice. This was against perhaps the most powerful defensive line in history up to that point and backed by well trained and seasoned troops.

Another poignant example would be the multiple defensive lines the Germans held in Italy, especially the Gustav and Gothic lines, and the Atlantic Wall that was supposed to repel an allied invasion of France, during “World War 2.” Keeping in mind the natural defenses the Italian peninsula offers, and the skill and tenacity of the German soldiers, these should have been ideal defensive lines. Indeed, the allies only breached these defenses after long and costly battles, especially around Monte Casino. However, numbers, firepower and stubbornness can, and often does, eventually succeed and the German defensive lines in Italy were all ultimately overrun. While one could argue that the allies only succeeded due to their material advantages, it should be born in mind that 99 times out of 100 it is the weaker adversary (at least in terms of numbers and resources) in any real, or potential, conflict that builds defensive lines, and it should not come as a surprise that their enemies are willing to use their superiority in order to defeat them. Yet to be fair to the Germans it could be argued that they constructed such defensive lines in Italy to delay the allied advance up the Italian boot, not to stop them indefinitely.

As for breaching the Atlantic wall the allies benefited from overwhelming firepower, meticulous planning and a brilliant deception plan that led the Germans to believe the invasion was supposed to take place in the Pas-De Calais region. Additionally, besides the fact the Germans simply did not have the time, or resources, to adequately fortify the whole Atlantic coast of occupied Europe, the German high command doomed any chance of repelling the allied landings when they failed to concentrate their panzer divisions near the beaches of the most likely landing sites.

An almost amusing example of how easily supposedly strong fortifications can be breached would be the Egyptian conquest of the Bar-Lev line guarding the east bank of the Suez Canal in 1973. The Israelis had constructed a massive sand beam nearly 100 feet tall almost running the entire length of their side of the canal. It was said to be so strong that some armchair generals believed it could only be breached by nuclear weapons. In the event the Egyptians defeated the formidable sand beam in a matter of hours by simply watering it down with high pressure hoses!

However, it can be assumed there are examples of defensive lines succeeding outright in conventional warfare. Yet, admittedly the author is only familiar with one example and that is the Lines of Torres Vedras guarding the British presence in Portugal during the “Napoleonic wars.” However the lines of Torres Vedras succeeded due to very specific conditions; conditions which other defensive lines seldom meet.

Firstly, the defensive lines could not be flanked because they were built from coast to coast and the British navy controlled the sea lanes. Secondly, the French army in Spain did not possess the necessary firepower to breach its powerful fortifications. Thirdly, the British had conducted a scorched earth policy while retreating through Spain and the French army was suffering from significant shortages. Lastly, the front on which the lines were constructed was relatively narrow which allowed the British and Portuguese forces to man the defenses in strength. Needless to say such conditions have seldom been met in the history of warfare and this probably helps explains why so few defensive lines have been as successful as those of Torres Vedras.

A seldom mentioned consideration regarding the inherent liabilities of defensive lines is that they tend to be inordinately expensive to build. While they usually look impressive one wonders how many planes, tanks, artillery pieces, or other critical weapons of war could have been built in their place. Indeed, while touring the Maginot line near the beginning of “World War 2” Field Marshal Alanbrooke was fascinated by such a marvel of engineering but was ultimately unimpressed saying it “gave me but little feeling of security, and I consider that the French would have done better to invest the money in the shape of mobile defenses such as more and better aircraft and more heavy armored divisions than to sink all this money into the ground.”

However, if defensive lines mostly fail in conventional warfare, they can be quite successful, at least in tactical terms, in counter-insurgency and counter-terrorism. Indeed, given that insurgents and terrorists are by nature usually weaker in numbers and firepower than their opponents they find it nearly impossible to breach, let alone neutralize, defensive lines. While admittedly defensive lines have been used less extensively against irregular opponents, not least because it is much easier for them to infiltrate across long borders, or via the coast vs. divisions of soldiers, when they have been used they generally have a better track record then those designed to stop conventional attacks. The usual, though not exclusive, prerequisites for this success are obvious; relatively short borders, open terrain, and well armed and motivated forces patrolling the area in question. Needless to say, these are conditions that are seldom met as successful insurgent movements tend to thrive in countries with porous borders, difficult topography and corrupt government and military personnel.

While it can be exhausting looking for examples of defensive lines that have succeeded in conventional warfare, there are plenty of examples regarding the success of defensive lines in asymmetrical warfare, at least in a tactical sense. The Morice Line during the “Algerian War,” Hadrian’s Wall, Chiang Kai-shek’s use of Block House warfare against the Communists during the “Chinese Civil War,” and the barriers erected by the Israelis to surround the Gaza Strip and West Bank were all unequivocally successful in severely reducing the capabilities of insurgents, terrorists, freedom fighters, or whatever terms people label such irregular movements depending upon their political biases or sympathies.

The Morice line was built on the Algerian-Tunisian border by the French during the “Algerian War” to stop the vast flow of weapons, men, and supplies reaching the F.L.N. (an insurgent movement dedicated to liberating Algeria from French rule) fighting inside Algeria. While the French usually have a bad reputation, mostly deserved, regarding their policies aimed at quashing the F.L.N. insurgency, the construction of the Morice Line, and an equivalent line along the Moroccan-Algerian border, proved to be an unqualified tactical success. Indeed, these defensive lines all but cut off the F.L.N. from the outside world and quashed any chance of them defeating the French militarily inside Algeria.

Hadrian’s wall was also successful as it stopped barbarians from invading Rome’s colony in Britain. As the border between the colony and barbarian territory was not very long, and as the Romans had naval supremacy, it was not unduly hard to plug this hole in Rome’s territorial expansion. While it is not clear regarding the ultimate purpose(s) of the wall, it is clear that no major hostile forces infiltrated Rome’s British colony as long as it was adequately garrisoned.

Chiang Kai-shek’s use of block house warfare in the “Chinese Civil War” is admittedly a bit different regarding defensive lines as the defenses were not located on any border and were not meant to be permanent but the same principles regarding its use applies. Instead of trying to keep insurgents out of specified territory, the plan was for Chinese nationalist forces to enter communist areas, build block houses and defenses, secure the area, then move further into the interior and repeat this process again and again. The Chinese nationalists did this on all sides of the communist region to surround the whole area, then used the multiple layers of blockhouses and defenses to squeeze the communists and limit their mobility. This was significant because whereas conventional forces fighting irregulars rely upon numbers and firepower to win engagements, irregulars use their usually superior knowledge of the terrain and maneuverability to engage in surprise attacks against soldiers to compensate for their material disadvantages. Isolated from other insurgent forces, cut off from their support base, and at a distinct advantage when fighting the well placed, numerically superior and better equipped nationalist forces, the Chi-Coms (Chinese communists) were eventually forced to break out of the encirclement and conduct a desperate retreat of more than 6000 miles to north eastern China.

Likewise the barriers built to stop terrorist infiltration from the Gaza Strip and the West Bank to Israel have proven to be a significant tactical coup. Given the open terrain, the relatively short borders, and the considerable amount of men and resources the Israeli Defence Forces have invested in the project, it is no surprise that terrorist attacks launched from Gaza and the West Bank have fallen to virtually nothing. Whatever the moral or humanitarian effects these walls have had regarding the Palestinian populations of these territories (and they are not inconsiderable) there is no doubt the barriers have accomplished their stated aim.

However, while the author has stated that defensive lines in asymmetrical warfare can have exceeding good tactical returns, he also noted that they are not as successful in the long term, or in strategic terms. Once this implication has been considered, it is no surprise that just as in conventional warfare defensive lines are ultimately unsuccessful in irregular conflicts as well.

Looking at the last four examples, one sees that the insurgent/terrorist movements in all these cases were not decisively defeated at all. The F.L.N. held on in Algeria until the ultranationalist Pied Noires and overly militant French army shot themselves in the foot, and alienated so many Frenchmen regarding their brutal behavior, that even the proud Charles De-Gaulle decided to give up Algeria. Hadrian’s wall did nothing to stop the growing decadence in the Roman Empire that ultimately led to the Romans abandoning their British colony. Even the 6000 mile retreat of the Communists in China was not enough as the “Sino-Japanese conflict” severely degraded the Nationalists and ultimately strengthened the Communists so much they won the military contest after the “Second World War.” As for Israeli success regarding her walls surrounding the West Bank and Gaza, it may have more or less stopped border intrusions, but did little to stop her enemy’s from acquiring rockets and missile that have led to two significant wars, in Lebanon in 2006 and Gaza in 2009, let alone crush the said organizations bent on her destruction.

Inevitably, this is a consequence of the inherent differences regarding victory in conventional war vs. victory in asymmetrical warfare. While victory in the former is usually the result of military means (taking a capital city, destroying an army, cutting off a force’s lines of communication, etc.) victory against terrorists or insurgents is usually the result of more economic, political, or diplomatic considerations. These usually involve winning the relevant populations’ hearts and minds, addressing grievances, and improving their political and economic standing. Or alternatively, a disproportionately bloody solution can work if the population believes the assailant will do anything necessary to quash dissent. Britain’s successes in the “Malayan Emergency” and in Northern Ireland are examples of the former approach, while the German genocidal tendencies in Namibia and Syria’s massacre of 10s of thousands of its own citizens in Hama in 1982 are examples of the latter approach. Needless to say the former solution is suitable for democracies, while the latter solution is used almost exclusively by authoritarian and totalitarian regimes. Either way it is apparent that while defensive lines can serve a purpose regarding such means, they are obviously not decisive in themselves.

None of this is to suggest that defensive lines or fortifications do not have an important part in warfare, conventional or asymmetrical. In the case of acting as a so called “trip wire” they can fragment an enemy’s advance of at least determine their likely axis of advance. Additionally, they are extremely useful, in multiple layers, at delaying a strong advance until a counterattack can be organized. This refers to the concept of “defense in depth,” and has been used to great effect in instances such as the “Battle of Third Ypres” in “World War 1” and the “Battle of Kursk” in the “Second World War.”

No, the point at which defensive lines become counter-productive is when they are expected to perform miracles and defeat whole armies and insurgents by themselves. Rather than being seem as either trip lines or a means to delay, they become the hope of the nation and contribute to a bunker, or “Maginot,” mentality. It should be clear that the author does not think defensive lines, even overly expensive ones such as the Maginot line, are useless. Had the French constructed the line to the English Channel or at least to cover the Ardennes forest they probably would not have been defeated by the Germans, or at least would have held out longer than six weeks. Yet besides such defenses the French needed to be bold and offensive minded and concentrated their forces for an attack on the Germans as the Maginot line allowed their army to do so.

Unfortunately, and ironic as it sounds, this is what defensive lines are supposed to accomplish. They are supposed to substitute concrete and barbed wire for men so a nation can concentrate its army and fight boldly against the enemy, and not be expected to serve as a rampart to be attacked in force by a foe with any common sense. Yet perhaps it is unsurprising that nations that put so many resources “into the ground,” as Field Marshal Alanbooke would put it, should not be expected to have the most offensive spirit when it comes to warfare. Allowing an army to concentrate its forces more effectively, along with the other uses stated above (serving as a trip line, fragmenting an attack, or delaying the enemy) is what should realistically be expected of defensive lines 99 times out of 100.

In all of these means defensive lines have an important purpose, but when they are depended upon to stop a powerful and innovative enemy on their own, or stop terrorism or insurgency cold, the historical record regarding their success should be labeled as “not good enough.”

Some of Clausewitz’s Ideas

Carl Von Clausewitz was a Prussian Staff Officer during the Napoleonic Wars.  After Napoleon was defeated at Waterloo, Clausewitz devoted his spare time to studying the conflict as well as the nature of war itself.  Before he died, he had nearly finished a manuscript that would be known as “On War,” and would prove to be the most influential book on warfare in the Western World (Sun Tzu’s “The Art of War” being the quintessential book in the East).  A smaller work, “Principles of War”, was written when he was the adjutant of Prince August Ferdinand of Prussia.  This is a relatively small, but informative book, on generally strategy and tactics.  While it is not as enlightening as “On War,” it is certainly worth a look.

After Clausewitz died, his wife dutifully published “On War.”  Clausewitz warned in a letter that if he did not finish the work before his death that it would be subject to “endless misinterpretation” and “the target of much half-baked criticism.”  These words now seem prophetic given all the confusion and criticism his book has attracted.

However, if you read “On War” patiently (as I have twice) and study some of the literature about Clausewitz you will find that most of his ideas are relatively simple to grasp.  Given that the book is smartly categorized, and that it was meant for soldiers, not scholars, it is a relatively easy, if long, read.  There are dated parts regarding tactics, but these are still interesting, if only to see how warfare was waged during his time.

While we can never know for sure what Clausewitz’s final edition would have looked like, there are some near certainties we can grasp.  Clausewitz was a big fan of theory for the sake of providing soldiers with a decent background of war, but never to be followed like dogma.  He obviously believed that hard earned experience on the battlefield, and natural leadership qualities, would produce a better general than an academic who seldom left his study and could never comprehend the pressures of war.  He clearly realized that whereas strategy is eternal, tactics change from one era to the next.  This is why, despite being unfinished, his book, which focused mostly on general strategy, is still relevant today, while other books that focus too much on calculations and tactics, like Jomini’s “The Art of War”, are largely obsolete.

However, whereas Clausewitz would never say there are rules of warfare, he more or less admits that there are “a whole range of propositions” that “can be demonstrated without difficulty.” These so called propositions are not doctrine, but rather general truths of war, meaning that they will be correct the vast majority of times.

Of all Clausewitz’s ideas perhaps the most famous is that “war is nothing but a continuation of politics by other means.”  This may seem so obvious that some may wonder if it is worth mentioning at all.  However many soldiers seem to have misinterpreted the relationship between generals and politicians that Clausewitz had in mind.  Indeed, many soldiers who have read his book either downplay the fact that Clausewitz believed politicians should always have the final say, or conveniently ignore it.  For the countless amounts of soldiers who have memorized the quote above, there is perhaps a handful who remember that Clausewitz wrote “the political object is the goal, war is the means of reaching it, and means can never be considered in isolation from their purpose.”

This is no surprise given that soldiers tend to be cynical, often with reason, about politicians and their goals.  While Generals with a solid grasp of history could easily list off many battles lost by political interference, they usually cannot cite a war that was won without civilian oversight.  While it is often the case, that in wars managed by soldiers alone, armies tend to enjoy better tactical success, it is often at the expense of political, economic, diplomatic, and domestic factors that tend to mitigate any gains that are made.

Examples from 20th century military history bear this out.  Germany’s military dictatorship in the last years of World War I provoked the United States into joining the conflict, and failed to mobilize the nation’s resources any more effectively than the democratic west.  During the Algerian war of Independence, where the French Generals had a freehand for most of the conflict, the brutal excesses of the French Army isolated France internationally, and turned the French people against the occupation.  And during the Vietnam War, the American generals won battle after battle, but focused too little on Counter-Insurgency Warfare (which all of its experts agree is more political than military) until it was pretty much too late.

Perhaps the second most well known quote from “On War” is “The defensive form of warfare is intrinsically stronger than the offensive form.” While this purely military concept would seem more straightforward than the last example, it has been just as misunderstood by generations of soldiers.  The excesses tend to run from those who consider it completely wrong (in other words those who think the attack is superior to the defense), and those who take it to the extreme.

The most obvious example of the former would be the mass slaughter, during the First World War, where offensive minded generals believed numbers and morale would crush trenches, barbed wires, machine guns, and artillery pieces.  And perhaps the best examples for the latter would be the countless nations that fell after investing so much time and resources into expensive defensive works like the Maginot Line that were easily outflanked by enemies with the slightest bit of imagination.  Just like the statement on politics, Clausewitz went into detail and explained very carefully the limits of the Defense and Attack, and once again generations of soldiers seem to have only absorbed, or completely ignored, the initial quote on the supposed power of the Defense.

Perhaps things would have been much clearer had Clausewitz said, “all else being equal the Defense is superior to the Attack,” instead.  This concept is obvious to all but the most obstinate soldiers.  It is generally accepted that to succeed in any assault you need a healthy superiority of numbers and equipment, either on the whole, or at least at the decisive point of the attack.  It should also be evident that if the attack was superior to the defense, then the weaker side in any conflict would have a better chance at success if it attacked rather than waiting on the defense.  However, history confirms that the vast majority of times the weaker side will stay on the defense because of the advantages the defensive form of warfare offers.

A clearer concept, and probably the one that most differentiates “On War” from lesser texts on warfare is the “fog of war,” or as Clausewitz termed it, “friction.”  Indeed Clausewitz wrote, “friction is the only concept that more or less corresponds to the factors that distinguish real war from war on paper.”  To put it simply, friction is the unforeseen accidents, mistakes, and circumstances that “combine to lower the general level of performance” of military operations.  Clausewitz cites the weather as an example, writing that fog can conceal the enemy, and that mud will delay the moment of forces.  Other examples could include the breakdown of communications, random accidents, or inaccurate maps issued by headquarters.

There are simply too many elements of friction to develop a theory to combat them all.  Clausewitz suggests that the only effective means of limiting friction is sound leadership backed by actual combat experience.  While this offers little hope to soldiers who have yet to go to war, Clausewitz, practical as always, does offer a few makeshift solutions.  Though he scoffs that peacetime training is a poor substitute for experience, he suggests that army manoeuvres interwoven with known elements of friction can he helpful.  In the cases were there are few officers in the army with battlefield experience he suggests enlisting officers from foreign armies, or even sending officers to serve with armies actually engaged in warfare.  Clausewitz assures us that these officers can have an impact well beyond their small numbers.  A chilling example would be the lessons learned by the Condor Legion in the Spanish Civil War that the German Army put into practice during World War 2.

Another novel Clausewitzian concept involves the distinctions between limited and unlimited warfare.  The main difference being that unlimited war, or as Clausewitz calls it, war to “render the enemy helpless,” is a life and death struggle between nations, whereas limited war is fought for distinct political goals.  Limited war is seen as more political, since the policymakers tend to micromanage much of the conflict to prevent escalation, limit casualties, and are ready to abandon their goals if the price of achieving them is deemed too high.  Unlimited war is less political as policy makers are usually willing to take the gloves off and allow the generals to use all means necessary to win.  Examples of limited wars would be the Korean War, Vietnam, and the First Gulf War, while examples of unlimited war would include both World Wars, and the Second Punic War.

It should be noted that wars that start as limited can become unlimited in certain cases.  The war of the Triple Alliance in South America, the Six Day War, and even the Second World War are examples of this.  In all these cases one country attacked another under the false assumption that other nations would not intervene in the war.

Unlimited war should not be confused with Clausewitz’s theory of absolute war.  This is a theory of indiscriminate violence and effort used to crush the enemy.  However Clausewitz dismisses absolute war as impossible because the political and moral considerations, as well as friction, will always restrain the supposed ideal level of violence absolute war advocates.  This is not hard to understand if one considers that even the most violent, and immoral regimes, throughout history, have shown restraint in applying violence.  For example, Hitler only allowed the bombing of British cities after the British bombed Berlin several times, and Stalin decided not to conquer Finland in early 1940 after a short but brutal war.  Needless to say both of these actions were not moral considerations, but political ones:  Hitler hoped the English would sue for peace and was trying not to provoke them, and Stalin was worried about possible French and British intervention in the event he tried to annex Finland.

The ideas of unlimited and absolute war lead to Clausewitz’s view that the most effective way of overthrowing the enemy is the destruction of his armed forces.  This is what he meant by “the wish to annihilate the enemy’s forces, is the first-born son of war.” This seems obvious after Clausewitz gives examples of the different means of defeating the enemy including conquering territory and attrition.  While occupying land is usually not decisive while the enemy’s army is still intact, and attrition is seen as a prolonged exercise in slaughter, an all-out effort to destroy the enemy’s armed forces usually promises a quick result.  However, it is also the most risky and bloody, at least in the short term, route to victory.  It is no coincidence that the lesser means are used more often in limited war, and the more aggressive ones in unlimited war.

“Next to victory,” as Clausewitz writes in “Principles of War,” “the act of pursuit is most important in war.”  This is where the trophies of the battle, prisoners and guns, are taken en mass.  This is because during most battles casualty rates are relatively even as long as both sides are committed to winning.  However, once the battle has been decided the loser begins to retreat and his forces lose discipline and cohesion and become easy targets if the winner can organize an effective pursuit.  The extent to which the winner manages his pursuit will determine the ultimate success of any battle.  If he allows the enemy no rest, as Napoleon did to the Prussians after Jena and Auerstedt, he may be able to crush all further resistance.  However if he pursues his enemy cautiously, as Marshal Daun did against Frederick Great, the enemy will probably recover.

Another concept concerns the concentration of force.  Clausewitz clearly explains this term by writing that “The best strategy is always to be very strong; first in general, and then at the decisive point,” and “there is no higher and simpler law of strategy than that of keeping one’s forces concentrated.”  He then goes on to state that it is foolish to detach forces from the main body if it serves no vital purpose.  The simplest way to describe the importance of the concentration of force is that bigger forces will usually defeat smaller ones.

One way of looking at his statement about being strong at the decisive point is that even if an army cannot match its enemy’s numbers on a whole, it can try to gain superiority at a certain location and defeat its enemy piecemeal.  Many of Rommel’s battles in North Africa against the British illustrate this perfectly.  Even though he was outnumbered in tanks, the British tended to divide their armour among several forces while Rommel kept his concentrated and destroyed them one by one.

Economy of force is a complementary concept to the concentration of force.  Whereas the concentration of force merely implies that the majority of one’s forces are centralized, economy of force dictates that all forces possible are used to engage, or at least distract the enemy.  Clausewitz merely remarked that one should remember “always to make sure that all forces are involved – always to ensure that no part of the whole force is idle.” While many people would assume that a concentrated force would use all its might to fight the enemy, this cannot be taken for granted.  Certainly an overly cautious army might only fight back with the forces that are directly engaged, or may hold back reserves for too long.  Even attacking armies may not use all their forces effectively; during the Battle of Cannae the Romans may have outnumbered Hannibal, but their ranks were so deep that most of its army was isolated from actual fighting until the Carthaginians had enveloped their army and it was too late.

One term Clausewitz seems to borrow from physics is Centre of Gravity.  He uses this term to describe the enemy’s source of strength, implying that neutralizing it is the quickest way to victory.  While many things can constitute a nation’s centre of gravity, it is often seen as either the armed forces, the capital of the country, an economical or industrial heartland, or in the case of a small country, the armed forces of its allied protector.  Although it would seem obvious that the defeat of the enemy’s armed forces would probably lead to the occupation of the other potential centres, this cannot be taken for granted.

Firstly, it is important to note that the defeat of the enemy’s armed forces may prove to be initially too difficult, thus opening up the possibility of attacking other targets.  Secondly, even if victorious an army may be so damaged or disorganized by combat operations that it may prove, at least initially, beyond one’s capabilities to occupy these potential centres.  This is especially true in the case of large countries like Russia. One need only look at Napoleon’s pyrrhic victory at Borodino.  He may have defeated the Russian army, and occupied Moscow, but his army was rendered too weak to seriously threaten Russia.  Thirdly, the potential of outside intervention in the conflict may limit the effects of defeating the enemy’s army.  Prussia may have been more or less defeated in 1806, but the intervention of the Russian army forced Napoleon to fight an extra year to complete the occupation of the country.

Often the seizure of the capital, especially in a country with a weak government, will be enough to force the enemy to sue for peace.  Likewise, the occupation of a country’s industrial heartland can produce the same effect.  It is hard to see a country like Germany make war with the Rhur region under foreign occupation.

Maintenance of the objective is a logical complement to the centre of gravity.  In the last chapter of “On War” where Clausewitz writes about creating a plan to completely defeat the enemy he begins by saying that “the first principle is that the ultimate substance of enemy strength must be traced back to the fewest possible sources, and ideally to one alone.”  This is referring to identifying, and then targeting, the enemy’s centre of gravity.  He continues by saying that “the second principle is:  act with the utmost speed.  No halt or detour must be permitted without good cause.”  This is a reference to maintenance of the objective.

The simplest way to describe maintenance of the objective is momentum combined with consistency.  In other words, once an objective of the campaign has been agreed upon (ideally neutralizing the enemy’s centre of gravity, or at least improving the general strategic situation) any distractions, or temptations, that arise during the campaign to change the objective must be ignored.

This may seem to be a contradiction of Moltke the Elder’s universally accepted maxim that “a plan never survives contact with the enemy.” However, this is not necessarily true.  First off, the theory of maintenance of the objective assumes, perhaps naively, that the objective of the campaign is achievable.  In the case of a campaign where the planners have chosen an objective that is totally unrealistic then no doubt they will fail in their attempt to accomplish it, and must either end the campaign, or try to switch the emphasis to something more attainable.  Secondly, Moltke’s maxim relates more to the field of tactics, where flexible planning and adaptation are a constant necessity.

The reason why it is usually not wise to change the objective during a campaign is that to switch armed forces, and resources, from one emphasis, to another, usually involves the loss of momentum for the offensive.  The vast majority of the time, any delay in the fighting, no matter how insignificant, favours the defender, as he will have shorter lines of communication, while the attacker is constantly stretching his farther.  As such, it is often the case that an army that is on the brink of being crushed, has time to recuperate while the erstwhile attacker slowly abates his strength in the pursuit of illusive gains.

Two examples include the Egyptian Army during the Yom Kippur War and the German Army during the 1942 campaign in Russia.

In the first instance the objective of the Egyptians was to gain the east side of the Suez Canal and hold it against Israeli attack until a cease-fire was declared.  During the first days of the war the Egyptians indeed managed to secure the east bank of the Canal and throw back several Israeli attacks.  It is very likely that had the Egyptians stayed on the defensive they would have been able to hold onto their gains until a cease-fire was declared.  However, Anwar Sadat, for political reasons, ordered the Army to advance upon the Sinai passes to relieve the Syrian Army that was being pummelled on the Golan Heights.  The Egyptian Generals, knowing they would be vulnerable to the Israeli Air force, and armour, once they were beyond the range of their Anti-Aircraft, and Anti-Tank, defences pleaded with Sadat to change his mind.  He did not, with the result that the Egyptian armoured forces were smashed, and the Israelis regained the initiative for the rest of the war.

In the second case the German Army, heavily dependant on oil, planned on conquering the Caucausus oil fields of southern Russia.  Initially the offensive went well, and the Germans advanced quickly towards their objective.  However, Adolf Hitler, tempted by the prospect of seizing Stalingrad, decided to split his advancing forces between the city, and the oilfields, the result being that the dispersed forces were too weak to take either objective.  Whether or not the Germans could have conquered the oil fields, or even Stalingrad, had they concentrated all forces on one of them is debatable, but it is certain they had no chance of taking both at the same time.

Having lived in an era heavily influenced by Frederick the Great, and Napoleon, it is no surprise that Clausewitz put a lot of emphasis on military leadership.  He described some of his opinions on the ideal qualities on leadership when he wrote that “if we then ask what sort of mind is likeliest to display the qualities of military genius . . . it is the inquiring rather than the creative mind, the comprehensive rather than the specialized approach, the calm rather than the excitable head.”  According to these conflicting qualities Clausewitz implies a commander who seeks answers, focuses on the bigger picture, and maintains his composure is preferable to one who dreams up unrealistic plans, gets bogged down in details, and is easily overwhelmed by events.

Clausewitz’s ideal commander is bold, decisive, and makes his own rules rather than being a slave to theory.  Clausewitz seemed to be mocking the latter when he wrote “pity the soldier who is supposed to crawl among these scraps of rules, not good enough for genius, which genius can ignore, or laugh at.  No; what genius does is the best rule, and theory can do no more better than show how and why this should be the case.”

If anything, for Clausewitz’s military genius “two qualities are indispensable: first, an intellect that, even in the darkest hour, retains some glimmerings of the inner light which leads to truth; and second, the courage to follow this faint light wherever it may lead.”  The first seems to imply the necessary knowledge one needs to command; ideally a sound grasp of military theory combined with actual combat experience.  The second would be perseverance and optimism; two vastly underestimated traits that are necessary in the chaos that is war.

For soldiers who are taught to refrain from attrition it may come as a surprise to learn that Clausewitz views it as not only normal, but also a valid practice.  When he talks about ways to make war costly to an enemy he writes, “the third, and far the most important method, judging from the frequency of its use, is to wear down the enemy.  That expression is more than a label; it describes the process precisely, and is not so metaphorical as it may seem at first.  Wearing down the enemy in a conflict means using the duration of the war to bring about a gradual exhaustion of his physical and moral resistance.”

It is significant that not only does he note the physical exhaustion of the enemy, but his moral resistance as well.  This is realistic considering that most wars, even desperate ones, are not fought until the utter destruction of either side, but until one of the combatants sues for peace.

In the case of the inferior combatant, attrition is used in the hope that either the enemy will give up, or some external development will turn the war in its favour, like the entry into the conflict of a friendly power.  In the case of the strong combatant, attrition is an assured, if costly, means of winning the war in the long term.

Attrition is not only normal; it is perhaps more frequently used than manoeuvre.  List any great war during the past few centuries and you will find examples in abundance.  In the time of Frederick the Great for every masterpiece like Rossbach, and Leuthen, there were countless slaughters like Zorndorf, and Torgau.  During the age of Napoleon, slaughters like Borodino were as common as manoeuvres like Austerlitz.  World War 1, without a doubt, was the ultimate example of attritional warfare.

World War 2, synonymous with mobile warfare, had no shortage of attrition in campaigns like Italy, Stalingrad, and Normandy.  The Korean War, with its dramatic advances and retreats during the first year, became a war of attrition during the last two years.  The American strategy during the first part of the Vietnam war, the emphasis on search and destroy missions and body counts, was a manifestation of attrition.
Finally, the Gulf War, with its smart bombs, and 100-hour land campaign, was preceded by more than a month of mostly one-way attrition against the Iraqi Army.

Yet, despite Clausewitz’s brilliance, there are parts of “On War” that are not so impressive.  Some of his ideas, especially regarding tactics, are dated.  This of course, is inevitable.  Another point is that he never had a chance to complete, let alone revise his work.  However, even though it is likely no one will ever write a more comprehensive, or realistic, book on warfare, the fact remains that Clausewitz’s work has a few flaws.

For one thing, in “On War,” there is next to nothing about Guerrilla Warfare, and not a single word on Naval Warfare.  Yet this is not as damning as some would assume.  According to Rupert Smith much of Clausewitz’s revisions to his book during his last years dealt with Guerrilla Warfare, and Counter-Insurgency.  Why most of it was never published is anyone’s guess, but probably the influence of Europe’s ruling elite that feared giving potential insurgents ideas.  Even without Clausewitz there are plenty of excellent texts on Guerrilla Warfare by Mao Zedong and good books on Counter-Insurgency by David Galula, and Roger Trinquier.  As for Naval Warfare, Julian Corbett borrowed heavily from Clausewitz when he wrote “Some Principles of Maritime Strategy.”

One of Clausewitz’s more dated theories is on the reliability of intelligence.  He more or less dismisses it saying, “Many intelligence reports in war are contradictory; even more are false, and most are uncertain. … In short, most intelligence is false.”  This is completely sensible if we consider the relatively primitive communications during his time.  However, in modern warfare, advanced communications and intelligence gathering capabilities can give armies distinct advantages.  This is seen by the indisputable advantage the American army has that allows them to engage in network-centric warfare.  Put simply, the vast amount of satellites, reconnaissance, Internet, and other communications assets gives American soldiers quick, and relatively accurate, information in real time.

However, such reliance on technology is not without risk.  While it is easy to track, pin, and defeat, a standing army in the field, it is relatively difficult to do the same with terrorists and insurgents.  Standing armies are hard to hide and are meant to directly engage the enemy, whereas insurgents, and terrorists, are purposefully elusive, and attack via indirect means.  This was demonstrated amply by the Iraq war; while the Americans destroyed Saddam’s Army with relative ease, it took several years to effectively pacify Iraq.

Another potential pitfall is the increasing risk of cyber-warfare.  Being overly dependant upon electronics, America’s enemy’s may be tempted to attack her in cyber-space rather than risk a direct engagement they would probably lose.  Even though America probably has the greatest potential to engage in cyber-warfare, and while many doomsday visions described by cyber-warfare experts seem far-fetched, there have been several examples of its potential power.

The 2007 cyber-attack on Estonia, supposedly initiated by the Russians, nearly brought the country’s government to a stand still.  There are also rumours that an Israeli kill switch inside the Syrian air defence system facilitated the attack on the supposed nuclear facility in Syria by the Israeli Air force in the same year.  The Russians made use of Cyber Warfare during their brief war with Georgia in 2008, hacking government websites and infrastructure.  Finally, there is much speculation that the Stuxnet worm was designed by the Americans, or the Israelis, to target Iran’s Nuclear Program, especially the Nuclear Reactor at Bushehr.

Yet arguably, the greatest threat to useful intelligence may still be the preconceptions of policy makers.  This is when policy makers, whether politicians, or senior military personnel, either pressure intelligence officers to produce Intel that confirms what they already believe, or simply distrust any information that is inconvenient to their goals.  History is full of such instances, from Stalin ignoring the most obvious signs Germany was about to attack Russia in 1941, the Israeli intelligence failure to predict the Yom Kippur War, and the American refusal to adequately check the validity of information on Weapons of Mass Destruction in Iraq before the invasion in 2003.

When one sees all the potential limits of intelligence during the Modern era, one wonders whether or not Clausewitz may have been right all along.

If there is any flaw with “On War” it could be that it is very long.  This could be inevitable considering the comprehensive approach he was taking, but the fact remains that compared to most texts on strategy Clausewitz’s work is a long read indeed.  There is a chance that had he lived he would have cut it down, but it is more likely the book would be even longer considering his plans to add extra materials.  While this consideration may seem superficial it should be remembered that soldiers, who actually fight wars, tend not to read as much as intellectuals, who generally do not to make great commanders.

For this reason it has been said, “Clausewitz is quoted but not read.”  It could be argued that, at least in the case of the U.S. Army, Jomini has had more influence.   However, to be fair many military colleges and institutions do make Clausewitz required reading.

Without a doubt there is much more wisdom, and some flaws, in Clausewitzian theory.  Clausewitz covers so much ground that it is simply impossible to address all his ideas in a single paper.  Yet despite the many ideas policymakers and soldiers have absorbed from “On War,” it is rare when they heed his warning that “no one starts a war-or rather, no one in his senses ought to do so-without first being clear in his mind what he intends to achieve by that war and how he intends to conduct it.”

…This is how great nations come to ruin.