Brains, Bullets and Flanks

Leo Murray

Brains, Bullets and Flanks
To cite this article: Murray, Leo, “Brains, Bullets and Flanks”, Military Operations, Volume 1, Issue No. 4, Spring 2013, pages 15-18.

Defence departments love using numbers to help them make decisions. Unfortunately, their evidence-based decisions are often biased because some numbers are easier to obtain than others. Physical variables like muzzle velocity, blast radius or firing rate are easy to measure; but for important things like morale or tactics, empirical data is very thin on the ground. This has steadily pushed defence departments towards the easy-to-measure world of attrition.[i]

The combat soldier has a similar problem. He can recite the range and firing rate of all his platoon’s weapons, but when it comes to understanding the enemy’s will to fight, he has to guess. He has a vague idea about how many rounds will be needed to suppress the enemy but he will usually err on the side of caution and fire far more than is necessary. Likewise, he might be fairly sure that the enemy will try to surrender once the fight gets near bayonet range but, rather than risk it, he will probably call up an air strike instead.

So, while defence departments and soldiers will cite Napoleon’s dictum that ‘the moral is to the physical as three is to one’ or Vegetius’ ‘an adversary is more hurt by desertion than by slaughter’, these phrases cannot compete with the arithmetic of attrition. Despite woolly concepts like ‘influence operations’, the weight of numbers biases armies towards weapons, training and tactics that provide more in slaughter than manoeuvre. The tactics are expensive, slow and often counter-productive; they have encouraged the Afghan insurgencies and will be of little help in ‘contingency’ war-fighting.

Tactical psychology is an effort to counter this imbalance by uncovering facts about the way people think and act in combat, then giving the facts to defence departments, training establishments and soldiers. This is not the type of data that one might get from the study of the accuracy of a weapon clamped into a bench vice or for a trained shot on a firing range (though such figures are often extrapolated to real combat in order to support procurement). The data gained from an assessment of tactical psychology will be less precise but far more relevant, as it is concerned with the chances that a soldier will even attempt to aim his weapon in a real fight.

Cutting Out

The easiest way to get a grip on tactical psychology is by looking at flank attacks. We all have an idea of the effects of flanking, but are we right? Is it an idea we would expect a defence manager to stake his career on or a young lieutenant to risk his platoon for?

To get a flavour of the effect, Corporal London, an Australian soldier in the Great War, relates his experience outflanking German soldiers in 1918:

‘We creep along by the embankment with Gaskell in front till we get to the house, then Scott and Warren go in while we keep cover. There’s no one home and no one out the back so we creep on back towards our line, checking the shell holes in this here barley field. We know Jerry’s close as there’s pipe smoke in the air and they’ve been doing their business in a little hole that Warren puts his hand in. We creep right up behind the first hole and there’s a machine gun in it and a couple of old hands. Gaskell coughs to get their eye, waves his revolver and they stick up their hands and start jabbering French at us. Warren waits with these lads and tries to clean the muck off his arm while the rest of us go on to the next hole.

This second lot are jumpy as they must have heard the first lot jabbering. They fire off a few shots but once we reply they throw up their hands. By now the third lot, the ones closest to our line, are on full alert. Straight away Gaskell goes on at them; this is by himself with just a revolver and a few bombs as he’s had to leave me and Scotty with the second lot. There’s a quick shooting match and they put up their hands too.

So now there’s four of us with fourteen or fifteen of them and their three machine guns plus all the papers and what have you all in the front crater trying to get back without getting it off our boys or theirs. So Scotty goes over and tells the company we’re coming then we just jump up and scamper back with Gaskell waving his revolver and scowling at the prisoners. By now I’m about blown with all that crawling but all I get is a quick breakfast and sent back out again.

That’s how it was with the cutting-out business in those days. We spend years getting ourselves slaughtered going at it head-on as we’d been taught, then it turns out that the Aussie way of getting round the back was the best all along.’

The cutting-out tactic was named after a drovers’ trick for separating livestock from the main herd. It was a favourite of Australian troops but all sides were using variations of it by the end of the war. Corporal London went out on another raid within the hour and helped bring in another eighteen prisoners. Other patrols from London’s company used cutting-out to capture sixty-eight men and seven machine guns that day. With only light casualties on both sides, a dozen men collapsed the German defence and the whole battalion was able to advance.

Sometimes flanking tactics developed intuitively because they were ‘the Aussie way’ but they usually grew from bitter experience, experimentation and copying the enemy (finding a flank was the German way too). The difference between the ‘walk towards machine guns’ tactic of 1916 and the various flanking methods being used in 1917 and 1918 could not be more stark.

1980s Revival

Corporal London’s account is an extreme example of the power of flanking, but we need a more balanced comparison to get an understanding of the flanking effect. The data mountain from our most recent wars includes very little on flanking or tactical psychology (though there have been a few valiant efforts to buck the trend), so it is necessary to compare two actions from the Falklands War that have been examined in great detail by staff college students: the battles of Mount Longdon and Mount Harriet.

As night fell on 11 June 1982, 3 Para was preparing to attack a reinforced company of the Argentine 7th Infantry on Mount Longdon. Seven kilometres further south, 42 Cdo was about to strike elements of the 4th Infantry on Mount Harriet.

The forces available for each attack were roughly equal, with both 3 Para and 42 Cdo based on three rifle companies with direct fire support from machine guns, anti-tank missiles and snipers. Each had indirect fire support from their own 81mm mortars, a battery of 105mm guns and a 4.5in naval gun. Though Paras and Marines might argue otherwise, both attacking units were picked men with similar levels of training and baseline motivation.

The defending forces were fairly balanced too. The company facing 3 Para on Longdon was reinforced by combat engineers, elements of a marine support company, and some snipers. All told, Longdon was defended by 220 men with .50cal and 7.62mm machine guns, recoilless rifles and anti-armour missiles. On Harriet, the defence had nearly twice as many men but no marines and fewer heavy weapons. There were 120mm and 81mm mortars on both positions. Both positions consisted of half-finished trenches and sangars perched on rocky ridges with most of their minefields, registered artillery and direct fire arcs running from north-west to south-west.

While each Argentine force had options for fire support from 105mm and 155mm artillery, the Longdon defenders were able to make better use of it on the night. Most assessments agree that, on paper at least, 42 Cdo had the toughest nut to crack, though this was balanced by the fact that 3 Para could not use one of their rifle companies due to the tight angle of attack.

The angle of attack made all the difference. While the terrain forced 3 Para into a frontal assault from the west, 42 Cdo were able to carry out a wide flanking move and assault from the south-east. Both attacks were supposed to go in silent, but both were sprung within a few hundred metres of the objective and instantly switched to being noisy and violent.

On Longdon, 3 Para were caught in murderous arcs of direct fire and increasingly heavy indirect bombardment. Small bands of men had to fight from one rock to another, taking casualties at every turn in what is still the bloodiest British battle since Korea. Forward movement was constantly held up by small groups of Argentine defenders fighting for every ridge and sangar. By the time they had secured Longdon, the assault force was exhausted and almost out of ammunition.

By the time Longdon was taken, 3 Para had eighteen men dead and forty wounded. They had killed maybe forty defenders and captured another forty. The remaining defenders were pushed off the position, taking an unknown number of wounded with them. After some confusion the uninjured survivors were reintegrated into the remains of the Port Stanley defence.

On Mount Harriet, 42 Cdo also had a stiff fight but it was far less intense than the battle to the north. Their longer approach meant that their attack was sprung after 3 Para had already attracted most of the Argentine artillery, but 42 Cdo was quickly in amongst the defenders anyway, making them a difficult artillery target. Like 3 Para, the marines fought with grenade and bayonet from one small position to the next. But unlike 3 Para, their main problem with maintaining momentum came from dealing with the large number of prisoners they picked up along the way.

All told, 42 Cdo lost two men killed and around twenty-six wounded. They had killed around twenty defenders and captured nearly 300. Very few Argentine defenders escaped to fight another day.

If we consider the two battles solely in terms of soldiers killed, wounded and captured, then Longdon was a three-to-one victory and Harriet was a twenty-to-one victory. In this instance a flanking attack was six times more effective than a frontal attack. Then of course we have to consider that while 3 Para was exhausted, 42 Cdo could probably have moved on to take a further objective had this been required.

Numbers Up

There have been many studies of flank attacks, with some staff college libraries containing half a dozen unpublished theses on the subject. But these studies tend to focus on large battles and on headquarters rather than the small teams of soldiers where tactical psychology has the greatest impact.

Added to this, a lot of flanking research is tainted by wishful thinking. It seems that in their desperation to counter the bias towards attrition, analysts and staff officers have been prone to exaggerating the power of manoeuvre. For example, the otherwise excellent Infantry in Battle (Infantry Journal, 1939) includes a chapter on ‘soft-spot tactics’ which only relates the most spectacularly successful examples of flanking by infiltration. Likewise, a flanking study conducted for the Army Personnel Research Establishment in the 1990s compared only famous flanking victories and notorious failures of frontal attacks.

This manoeuvrist bias reflects a natural tendency for historical data to under-report failed flank attacks – those that fail to find a flank are reported as frontal, those that find a flank but are ultimately defeated rarely occupy more than one line in a battalion war diary. It is also very hard to find attacks like Longdon and Harriet that allow attack and defence strengths to be balanced out.

Despite these limitations, historical analysis (the application of statistical techniques to military historical data) has compiled a selection of eighty engagements where reports from both sides have been used to counter the effects of exaggeration and wishful thinking. This work draws on the raw data in American, British and Canadian studies to show that, on average, flanking attackers suffer one-third of the casualties of the defenders, while frontal attackers take six times as many casualties as the defenders (see Fig 1).

Fig 1: Casualty share for frontal and flanking attacks

Fig 1: Casualty share for frontal and flanking attacks

Of the frontal attacks that were examined, none were successful unless they had an overwhelming manpower or firepower advantage (of at least six-to-one), while the flanking attacks often succeeded despite fighting at a numerical disadvantage. Even when frontal attacks succeeded, the enemy usually withdrew rather than surrendered, whereas successful flanking attacks tended to capture far more of the enemy than they killed.[ii]

A good chunk of the success of flanking is due to its purely physical advantages. Avoiding wire and minefields has an obvious benefit, as does the ability to negate carefully selected cover to shoot people in the back. Flankers can also fire along a line of defenders, rather than at a right angle, effectively giving each shot more chance to hit someone (or suppress them).

Flanking also tends to deliver a local force ratio bonus, for example at the point of the Mount Harriet assault, 42 Cdo was able to move along the thin edge of the defended zone, repeatedly engaging small groups of defenders. While 42 Cdo could only use a fraction of their force at any one time, they often had twice the usable combat power of the Argentine defenders.

Yet the problem of getting a large force around a flank and then fighting through a deep defended zone means that many flanking attacks do not have these advantages. In such cases they appear to win through a combination of psychological factors.

Tactical Psychology

The most commonly cited psychological effect is that flanking pushes defenders into a particularly nasty version of information overload. With their attention often split by a simultaneous frontal threat, the flanking assault is, in effect, giving defenders too much data to process. Even without a firebase holding the enemy by the nose, fire and movement on a flank is generally far more confusing for defenders than a frontal assault.[iii]

Extra uncertainty comes from the attacker appearing at unexpected places: How did they get there? Did they kill or capture everyone behind us? Have our flanking units bugged out without telling us? There is an organisational aspect to uncertainty, with the effort needed to reorganise the defence preventing a coordinated response and creating an ‘uncertain stumble’, where each man is focused on a different part of the threat.[iv]

In platoon and company engagements there is usually a compulsion bonus for the attackers. The attacking commander can put himself close to the point of decision, driving men on by his example and by exploiting the powerful coercive effect that comes from having the boss nearby. Meanwhile, the defending commander is most likely to be a hundred metres away, still expecting a frontal attack.

Flanking attacks tend to get in close before they are sprung so there is a proximity effect at work too, with most people having a very strong aversion to fighting at close quarters. Depending on terrain and weaponry, the effectiveness of fire drops off within approximately fifty metres of the enemy because everyone is suddenly much more aware of what a horrible place a battle can be.

Proximity is perhaps the most complex aspect of tactical psychology but the attackers, owning the initiative like they do, know that they have reached a point of no return – a point where the best survival option is to fight on. The defenders are not so certain, and often think they are at the last safe moment, a place where their best option might be to run, hide or surrender.

But if we discount uncertainty, proximity and all the rest, the very act of being outflanked looks to have its own unique psychological effect. Opinion is split as to where this comes from. Some analysts have suggested that it is biologically programmed and has something to do with our sense organs pointing forwards, as if we have an innate dislike of being blindsided. Others have focused on social learning to suggest that being outflanked is a culturally recognised disadvantage which radically recalibrates a soldier’s ‘is it worth it?’ calculation, greatly encouraging the innate freeze response to a threat.

The exact mechanism is unknown. What is known – as well as we can tell by assessing those eighty battles – is that if we subtract the physical bonuses and all the other known psychological forces, the pure flanking effect halves the chance of a man fighting. Put all these factors back together and on average a flank attack, if you can do it, is seven times more effective than a frontal attack.

The Future?

Sadly, as with most tactical techniques, the details of how to perform a flanking attack are largely forgotten between wars and have to be relearned by each new generation of combatants. Close tactical lessons do not readily translate to pamphlets or standing orders. They are often only transmitted successfully when veterans are taken out of the fighting to run training – a policy that Western armies have always had trouble implementing.

But the school of hard knocks is incredibly wasteful. It relies on soldiers surviving combat long enough to learn from their experience. It also needs soldiers to fight on a level playing field rather than one where, like Afghanistan, our side has all the firepower.

The solution is to give soldiers the facts about tactical psychology and the freedom to work out how to make best use of them. Unless this happens, defence accountants will stay focused on lethality and training will continue to play lip service to manoeuvre. Without an appreciation of tactical psychology, our soldiers will retain tactics that will be as unsuitable to the next war as they have proved to be in Afghanistan.


[i] This, in turn, has led to some dangerously mistaken conclusions. One of these, repeated in doctrine publications in various forms, is that ‘although set within a manoeuvre framework, the infantry battle is essentially one of attrition.’
[ii] Success by flanking generates different strands of positive feedback, limiting the development of a vengeance cycle (e.g. I’m fighting because you killed my mate) and, in a long war, indicating to subsequent enemies that surrender is a viable option. The absence of both these strands has been notable in Afghanistan.
[iii] An element of this can be seen in incident reports from Afghanistan, with patrols facing two or three insurgent teams often reporting that they are pinned down from eight or nine firing points and unable to prioritise or respond effectively.
[iv] Fast, combined-arms attacks have the same effect, splitting defenders between the best response for armour, infantry or indirect fire.