Tactics from Waterloo to the Bulge
The growing scale of battle
In many ways, the Battle of Waterloo in 1815 constituted a crucial turning point in the tactics of land warfare. Until then, even though weapons and methods had varied greatly, land battles had essentially been single events, taking up a few square miles and lasting no more than a few hours or a day at most. Consisting of formal trials of strength between the main forces of both sides, often enough battles resulted from a kind of tacit mutual consent to commence hostilities. Shifting an army from deep marching columns to thinner and wider fighting formations was a lengthy process; hence, battles very often took on a quasi-ceremonial, paradelike character and were attended by much pomp and circumstance. The short range of weapons—never more than a few hundred yards, usually much less—dictated lateral deployment in order to bring every available man (apart from tactical reserves) into action. Moreover, the means of communication, which had scarcely undergone any change since the dawn of history, imposed definite limits on the length of the fronts that could be controlled by a single commander—three to four miles at most. This in turn meant that the number of troops on each side very rarely exceeded 100,000, a limit that, as mentioned above, had already been reached by Hellenistic times. Indeed, whenever Napoleon brought more than 100,000 men into battle, he tended to lose control over some of them—as happened at Jena, when he forgot about three of the seven corps at his disposal. At Leipzig in 1813, 180,000 French troops faced almost 300,000 Prussians, Russians, Austrians, and Swedes, causing the battle to fall into three separate engagements that were hardly related to one another.
During the 19th century all this was to change, especially as the Industrial Revolution began to make its impact felt on the battlefield after about 1830. Following a century and a half of stagnation, small arms began to undergo rapid technological development. First came percussion caps, then rifled barrels, cylindro-conoidal bullets, breech-loading mechanisms, metal cartridges, and magazines. These improvements permitted tremendous increases in reliability, rate of fire, range, and accuracy—as exemplified by the French Chassepot rifle of 1866, which was sighted to 800 metres and was thus theoretically capable of hitting a target at six times the range of the old flintlock musket. Artillery underwent similar development as the old bronze or cast-iron muzzle-loaders gave way to rifled, breech-loading guns made of steel. From the middle of the century, the solid shot and canister that had long formed the principal types of ammunition were replaced by explosive shell, leading to another great increase in lethality and sheer destructive power.
As might be expected, these developments had a profound impact on tactics, even to the point where the very meaning of battle was transformed. Already during Napoleon’s time, presenting a solid wall of flesh to the enemy could result in exceedingly heavy casualties. As a result, some of his later battles—Wagram (1809) and Borodino (1812), in particular—were won by mass butchery rather than tactical finesse. Now, however, such methods became positively suicidal. In order to survive on the battlefield, troops, often acting against their officers’ wishes, had to discard their brilliant uniforms, lie down, take cover, and disperse. As a result, tightly packed formations disappeared or, in cases when they were retained by obtuse commanders, merely led to horrific casualties such as those suffered in Pickett’s Charge at Gettysburg in 1863. First in the United States, then in Europe, tactical formations began to dissolve: following the Battle of Königgrätz in 1866, the Prussian chief of staff Helmuth von Moltke expressed concern over the tendency of entire armies to melt into skirmishing lines. The ability of officers to keep their units apart, their men in hand, and their objectives in view declined, if it did not actually disappear. These developments puzzled contemporaries, who came up with the most bizarre ideas as to how to deal with them. In the end, they favoured armies, such as the German one, that adapted to the new circumstances by decentralizing command and making greater use of the individual soldier’s initiative.
Insofar as dispersal took place, it caused fronts to grow much longer and less cohesive. From the middle of the 19th century, this tendency was reinforced by the larger number of troops produced by conscription. As battles took up more space, the number of men within a given area declined very sharply. Within each army, fewer troops were actually in action at any moment, giving and receiving fire. This, in turn, caused battles to grow much longer. During the American Civil War, some battles, such as Gettysburg, lasted three days, and one week-long series of engagements became known as the Seven Days’ Battles. Since modern weapons permitted fighting at longer ranges, gradually a situation was created where the rear areas of armies could be brought under fire just as well as their fronts. Battles, in brief, ceased to be distinct events that could be well defined in time and place and easily identified by crossed swords on a map. During World War I, it became routine for battles to spread over dozens of square miles and last weeks or even months. And, as aircraft became increasingly effective during World War II, they went far to obliterate the distinction between front and rear—another symptom of the changes brought about by modern technology.
The longer that battles lasted, usually the less severe were the casualties produced on any particular day. Throughout the 18th century until the French Revolutionary Wars, armies had fought at the very most three major battles during a campaigning season, which was normally calculated at 180 days. These were bloody affairs, since a few hours of murderous, eye-to-eye combat could easily produce 20, 25, or even 30 percent casualties. However, post-1870 armed forces used their rifled weapons to fire at each other at considerably longer ranges; they also operated in a much more dispersed manner and very seldom brought all or even most of their forces together at a single point. Hence, although over a period of time losses could be just as heavy, they seldom suffered as intensely in a single battle. To suffer casualties in excess of a few percent of strength in one day, as happened to the British at the First Battle of the Somme in 1916, was an exceptional calamity. It was as if, in an instinctive response to the overwhelming power of the new weapons, the fighting became more prolonged but less intense—there being only so much terror that men could stand.
The power of the defense
The last years of the 19th century witnessed the development of automatic weapons in the form of machine guns. Artillery, too, was revolutionized by the addition of recoil mechanisms, which obviated the need to resight the guns after each round and therefore permitted much more rapid fire. As a result the infantry, no longer able to survive the storm of steel sweeping the open terrain, was forced to seek refuge underground. The ineffectiveness of charging cavalry was proved by the immense losses it took during the Crimean and Franco-German wars: unable to follow foot soldiers into underground shelters, it languished and finally disappeared altogether. The tactical defense, rendered invisible by the substitution of smokeless powder for black powder, became much stronger than the offense. This development, the first signs of which could already be seen in the 1850s, dominated the South African War (1899–1902) and the Russo-Japanese War (1904–05)—although most European commanders refused to look facts in the face until the butchery of World War I. During that war, fronts, manned by armies whose troops numbered in the millions, solidified into continuous trench systems that were sometimes hundreds of miles long. Often there were two and even three lines of trenches protected in front by belts of mines and barbed wire hundreds of yards thick. From the rear they were linked to communication trenches, which led into them and allowed reinforcements to arrive without leaving cover.
To overcome a well-entrenched enemy was something that could be achieved, if at all, only by tremendous concentrations of heavy artillery. Directed by forward observers and from balloons and aircraft overlooking the battlefield, artillery fired high explosive, gas, or—ideally, since the two called for different and even contradictory responses—a combination of both. The number of rounds fired could run into the millions; even so, an astute defender needed neither despair nor expose his troops to the physical and psychological effects of a heavy bombardment landing on their dugouts. Instead, leaving only a thin screen to hold the forward line, he could keep his main forces out of the guns’ range. As in Wellington’s day, the preferred location of such defenses—witness the so-called Hindenburg Line built by the Germans in 1917—was on the reverse slope of a hill or ridge. This denied the enemy observation, complicated his planning, and made it much more difficult for him to register his artillery on target.
In its highest and most developed form, the World War I defensive system consisted of a fortified belt several miles deep. Its main strength was not its continuous trenches but rather its being studded with well-positioned, well-camouflaged strongpoints. So long as the belt held intact, the strongpoints faced forward, bringing fire to bear and acting as observation posts for their own defending artillery. They were, however, also capable of mounting an all-around defense even in the absence of communication with one another and with the rear, thus obstructing the successful attacker as well as delaying and canalizing his progress. Standing ready immediately behind the belt were units (usually the size of regiments, sometimes entire divisions) held in reserve for launching counterattacks. In the German army at any rate, the commanders of such units were often authorized, not to say required, to act on their own initiative without waiting for orders from rear headquarters. The saving of time that was achieved in this way usually permitted local breakthroughs to be quickly repaired, as happened at Cambrai in 1917.
In the face of such defenses, the best-organized attacks were often helpless. Attempts to follow up artillery bombardments by infantry attacking in lines (the method selected by the British at the Somme in 1916) merely led to enormous casualties unequaled in warfare before or since. Later in World War I the Germans, commanded by Erich Ludendorff, developed a new offensive system. The usual daylong and even week-long bombardments were replaced by shorter, more intensive barrages in which gas and high explosive were carefully coordinated and which lasted no more than a few hours. To maintain surprise, no registration rounds were fired, the guns being laid solely by means of mathematical calculation and weather reports. The attacking troops were organized in small, self-contained storming parties. Armed with light machine guns, hand grenades, light mortars, and even some specially designed artillery pieces light enough to be manhandled, they used so-called fire-and-movement tactics. Each subgroup advanced, took cover, and provided the other with covering fire in turn. Like other World War I infantry, the German Sturmtruppe suffered greatly from a lack of mobile radio linking them with their own artillery as well as rear headquarters, but, unlike the rest, they were able to overcome this problem to some extent by operating in a decentralized manner, filtering between enemy strongpoints and bypassing resistance in order to penetrate into the rear.
Regarded from a purely tactical point of view, the German methods were very effective. Having proved their worth at Caporetto in 1917, during the great offensives launched in the spring and early summer of 1918 the Germans repeatedly succeeded in driving through British and French defenses. Ultimately, however, they were brought to a halt by the inability of logistic services to follow up over the devastated terrain. Deprived of even the most elementary supplies, the attacking troops were forced to resort to looting and soon lost their cohesion. Sooner or later the breach they made was sealed by the other side’s reserves, leaving them stranded in the salient they themselves had created and thus exposed to counterattacks on three sides. It should be added, though, that the World War I offense stood a much better chance of succeeding in theatres other than the Western Front, including, in particular, Poland, Russia, and Palestine. In those theatres modern weapons—especially heavy artillery, which could not be brought up over underdeveloped transportation networks—were often less dense on the ground. Hence attacks could succeed, and in some circumstances even cavalry remained effective.
Another offensive weapon destined to have a great future was the tank. The idea of employing armoured vehicles on the battlefield was not new, dating back at least as far as Leonardo da Vinci (before 1500), but they first appeared on the battlefield in 1916 at the Somme. World War I tanks were either “male” or “female”; that is, they were armed either with cannon up to 75 millimetres in calibre or else with machine guns. They could drive through wire and cross trenches (sometimes by dropping fascines into them), crush or neutralize strongpoints, lay smoke screens, and serve as mobile cover for the infantry to follow. During the last two years of the war they were often employed in all these roles, sometimes with success (as at Amiens in August 1918) and sometimes without. Success often depended on numbers: tanks operating individually or in small groups, it was found, did not have sufficient shock effect. Their armour, only 12 to 16 millimetres thick, could be defeated by a determined defender employing field artillery, heavy machine guns, or even special rifles firing heavy ammunition. On the whole, then, early tanks were essentially motorized versions of ancient siege machines. Given their short range, low speed, and general clumsiness, they were suitable for little else.
