The Heavy Force/Light Force Mixup

In the time I have had the privilege of working with your editor, we have agreed about most things. But we have h a one or two fruitful clashes too, and this article is the product of one of them. “Light forces...,” he wrote me, “are more suitable for defensive purposes than the more offensively suitable heavy forces.” A recent multiple feature in Infantry magazine shows that this is indeed the U. S. Army’s thinking. As it is the precise opposite of the conclusions I have drawn from my studies of the past few years, there is evidently food for thought. This disagreement represents two theories coming down to earth and colliding head-on. In attrition theory - the tradition of American and British military thinking culminating in the 1976 edition of FM-100 - heavy forces are for attack and light forces may be used in defense on the principle of economy of force. Maneuver theory, as promulgated in the 1982 edition of FM 100-5 and applied in the Starry/Richardson “AirLand Battle” and the Rogers “Strike Deep” concepts, sees offensive power as being developed not so much from mass as from momentum. No need for the addicts of attrition and the masters of maneuver to come to blows, though! In a book now in press (Race to the Swift - Thoughts on Twenty-first Century Warfare. Brassey’s, London. July, 1985.) I have demonstrated, to my own satisfaction at least, that, once hostilities have broken out, maneuver theory ceases to contradict attrition theory and embraces it, adding a third and dynamic dimension to it. In an offensive operation based on maneuver theory, the holding force action, including the break-in battle if one has to be fought, remains attrition-oriented and thus calls for heavy forces. How Light is Light? Comparing and contrasting “Zight” with “heavy” tends to mask the equally important distinction between light and light mechanized. As a result, the hi-tech light division concept piloted by 9th Infantry Division -or at least the 1984 form of it - has fallen neatly and hard between these two stools. HTLD 84 could put only 648 men, 4.5 percent of its strength, in foxholes (as o p posed to the U. S. airborne division’s 33 percent); yet it lacks protected mobility. Light mechanized forces have been out of fashion in the U. S. Army for 25 years or so. Although I have heard a number of tactical justifications for this, I suspect it is at least partly due to the extraordinary and disastrous history of American armored reconnaissance vehicles. At the same time, the farsighted preference of the cavalry for the rotary wing has diverted manpower and money from the light mechanized area. Like M2 Bradley, the M3 cavalry fighting vehicle (CFV), is essentially a heavy-force vehicle, the more so as it is too wide for the C-141B Starlifter aircraft. Perhaps we can fairly define alight mechanized force as a force mounted in airportable, amphibious, cross-country vehicles which provide all-around armor protection and a full range of mounted firepower. To this we must add two riders - the force is likely to contain a rotary-wing element equivalent to that of the heavy division’s air cavalry attack brigade (ACAB); and its fie-power may exclude the latest main battle tank gun. In these terms, the U. S. Army has neither the equipment in its inventory nor the formation in its struo ture. The technology to field alight mechanized division, with the 105 mm tank gun in its armory, is now available. The need for it in a number of possible intervention theaters is selfevident. The question is whether light forces can contribute to the defense of the NATO center and, if so, how. I have written extensively elsewhere about special forces, semi-special forces like paratroops and helitroops, and light infantry. Here I want to address the role of the light mechanized force both as a component of the main maneuver force in Europe, and in intervention. Mass and its Key Multipliers All armies I know of, including the Soviet Army, the Wehrmacht, and the pre-1973 Bundeswehr, reckon mass in terms of numbers of men. Attempts to work with a number of other primary parameters convince me that this is the only practicable one. Yet in equating numbers of men ARMOR 37 to physical combat worth, one is making a host of hidden assumptions. Among these is that every combat and combat support soldier, from the paratrooper to the chopper pilot to the heavy rocketeer, has the same chance of survival. While I question the British Parachute Regiment’s contention that a paratrooper has a life expectancy of only six hours in contact, this sweep ing assumption is patently untrue. We, therefore, need to find away of starting from numbers of men and arriving at an estimate of physical combat worth. After following many a false trail and primrose path, I found that one can do this with one or both of two key multipliers. The first of these, organic weight per man, gives one a compound parameter of physical fighting power. This applies mainly to attrition theory and the attritional component of maneuver theory. But it also represents the potential threat conveyed by the mobile force in an operation based on maneuver theory. In battling my way towards this notion, I used Soviet formations (1980-ish vintage) as models and amved at these figures, deliberately rounded to preempt nit-picking: Airborne Assault Brigade, including helicopters - 0.85 tonnedman. Airborne Division, c. 33 per cent BMD-mounted, excluding transport aircraft - 1.25 tonnes/man. Mechanized Division - 2.5 tonnes/man. Tank Division - 4 tonnes/man. These figures strike me at least as making very good sense. On ballpark figuring (since I do not have all the relevant data), the US. Army’s Heavy Division 86 seem to come out at around 3 tonnes/man, the figure being pulled down by the ACAB and the large softskinned tail. A similarly structured light mechanized division, based on a 15-to l&tonne in-divisible load and articulated heavy weapon platforms, would give a figure of rather under 2 tonnedman. The principal maneuver multiplier is tempo, which one might roughly envision as operational rate of advance. For a maneuver-based offensive operation, the Soviet Army regards an all-arms army, a tank division, and an airborne assault brigade as having roughly the same combat worth. In an earlier analysis using simply mass; i.e., number of i I men, and teml: momentum, I founa mengures maxn-ed the Soviet estimates of combat worth to the nearest order of magnitude. But adjusting mass by organic weight per man and then multiplying by tempo brings one much nearer the mark - as common sense suggests it should. Similarly, amphibious performance, better trafficability, and a higher cruising speed might give alight mechanized force a 50 percent advantage in tempo over a heavy one. Thus, as long as it can exploit its speed, alight mechanized division would have about the same physical combat worth as a heavy one. We shall see in a moment that a comparison by types of combat and role largely bears this out. This brings me, though, to two pitfalls I must highlight before switching from this approach. Physical combat worth is not an absolute quantity, only a relative one. It depends on what the US. Army so aptly summarized as ME”-T conditions. (For thebenefit of non-American readers, METT-Tis a complex parameter which takes account of Mission, Enemy, Terrain, Troops and Time.) In many METT-T conditions associated with intervention, organic weight per man may be a powerful demultiplier, and high tempo may be wholly unrealizable. Second, all this figuring is, as Mahan puts it, “a guide which warns you when it is going to go wrong.” It takes no account of the ovemding factors of generalship and morale. Structure and Equipment Another possible reason for the U. S. Army’slight mechanized void is the way the 1986 force structure plan stepped back from two brinks. With the emphasis still very much on the NATO center, the division remained the key structural formation. For a single-role army like that of the Federal Republic of Germany, this may still make sense- although the Soviet Army, designed to operate on central land lines, is showing signs of moving towards a brigade-based organization for some types of forces. But with the direct and real cost of the individual rising wen morerapid-ly than his combat worth, the arguments for a structure based on self-contained brigades (brigade groups) What is more, the inte-graxion 01 a brigade’s-worth of air cavalry into the division, tactically desirable as this may be, makes it expensive, unwieldy, and complex to handle. Once force structures really begin to reflect the need to shift the combat arm/artilleryratiofrorn3-b1toward 140-1, this unwieldiness will run wild. Above all, where intervention over long or medium air lines is called for, even a modest division mainly composed of any one type of force is out of scale with the airlift available for deployment and logistic support, while a division-sized task force made up of different types of brigades - say air cavalry, light mechanized, airborne, light infantry - is in the right ballpark. Alight mechanized brigade will require a- bout the same airlift as, say an airborne division; if the METT-T conditions areright, it should have around the same combat worth. The second and more evident brink is the failure (against USAARMS’ recommendations) to reorganize the combat arps. Here again, a single-role army like the Bundeswehr can just forge ahead and integrate armor and infantry. For a multirole army faced with mounting emphasis on intervention, the problem is less simple; armor and infantry alike are already pulled in more directions than they can reasonably cope with. But the key to a value-for-money light mechanized force is clearly an organically and intimately integrated combat unit. Apart from all the other factors going for it, this is dictated by technology. In the heavy maneuver force, the need for a point defense antihelicop ter weapon system to protect the MBT is steering several armies towards the idea of a MBT/IFVpair. In an airportable light mechanized force, the vehicle pair concept is dictated not so much by the state of the art as by the shape of the man. I have rehearsed the arguments at length several times over in your columns and elsewhere; here I will just summarize my current view of them. Strange as it may be, the US. Army has twice embarked on third time lucky projects and come up with winners. The MI is a fine tank. And there can now be little doubt that the M2 is a worldbeater as a squad IFV. But to cut a M2-like 38 design to Starlifter size, you have to make it a fire team (half squad) IFV. This means seven vehicles per mechanized platoon. Throw in alight mobile protected gun (LMPG) per squad, making up the equivalent of the MBT/IFV pair, and you have a 10-vehicle platoon. This is out in terms of tactical handling. So your squad has a pair of fireteam IFVs or fire-team vehicles ( n V s ) -the FI7r (cannon), probably also a gun such as the Israeli IMI 60-mm HVMS in some kind of cleft turret or semi-external mounting. The kinetic energy (KE) performance of this gun is claimed to be about that of spin-stabilized 105-mm APDS - a claim borne out by the way US. work in this area is looking at calibers down to 40-mm. The FTV(C) is the platoon command vehicle, with a lookalike light command vehicle (LCV) for company and battalion headquarters. With guided, antiarmor mortar projectile (GAMP) coming into service, the light mortar vehicle (LMV) ranks at least equal to the light TOW vehicle (LTV) and the LMPG in importance, and either the LTV or the LMPG might be discarded. The Reinmetall 105-11 SLR, 105 mm tank gun ammunition, will fit on theM2with acleftturretor(semi-) external mounting. But no way can this gun be made compatible with a narrow 15-tonne vehicle and a trunnion height of over 2 meters. By contrast, a dedicated topless LMPG mounting this gun is feasible within the Starlifter loading gauge at 17 or 18 tonnes; and novel hull configurations might get this figure down below 15 tonnes. A powerful LMPG firing existing ammunition is thus available if required. Figure 1 shows alight mechanized battalion of this kind, that I developed last year. Being intended as a basis for discussion, it is on the lavish side, including LMPGs, LTVs and mortars as support weapons. Figure 2 indicates how a self-contained brigade built around it might look. Given suitable METT-T conditions, the battalion has roughly the same physical combat worth as a standard infantry brigade; and it requires just about the same number of C141Bs to lift it. Likewise, the brigade roughly equates in both respects to a standard infantry or airborne division. The company is the structural equivalent of a balanced tank- 180 nnc 20 6 SCVi f2g LCV ughtcomMndv. Mc* LTW Light TOW Vehick LMPO: Light Malm Promcml Gun LMV bgM Mortar V e h i i FN(C): Five Twm V o h i i (Cannon) SCV Scout Vehicle (Cannon) FN(G): Fire Twm Vehicle (Gun) Figure 1. A Possible Light Mechanized Battalion Structure x 166mm 12) SlGlNT

(1) See Fig. 1 (21 166mm GUNS AND YORK EQUWALENTS tracked at%ahmd, 2 x lbtunitsrch Figure 2.

SUPPORT a infantry company combatteam, and can put about the same number of men in foxholes. I will use this brigade and combat battalion as models in examining the role and worth of light mechanized forces. Light Mechanized Force on NATO Center The arguments being put forward for the use of a heavy-light mix in 7 (US.) Army look to be based on versatility and speed of reinforcement. Briefly, the US. needs first-rate forces of various types that are suitable for intervention; some at least of these must also be suitable for employment on the NATO center. This is a fair enough argument. But one can justify the heavy-light mix in terms of operational advantage; and this may be a more fruitful way to address the problem. All armored vehicles, including the latest MBTs, are wide-open to top attack. This threat is growing apace; by the end of the century it is likely to be the dominant antiarmor threat. Given this, the light mechanized is less powerful than the heavy in two respects. With a caliber of 60- mm or so, the FSV(G)’s gun will defeat the MBT front only at short and medium ranges - out to 2,000 meters at the most and maybe 1,500 meters. Similarly, the light force lacks a vehicle with the MBT’s survivability in face of KE attack on the classical frontal arc. This means that alight mechanized force cannot deliberately confront a force containing MBTs on open ground. It cannot carry out a frontal attack (such as a break-in) against a deployed force containing MBTs. Likewise, in positional de-ARMOR 39

“... Alight force needs room to maneuver at speed if it is to develop its full combat worth...” fense, it cannot maneuver in the open or move forward under the guns of an attacking force containing MBTs. Sure, alight force needs room to maneuver at speed if it is to develop its full combat worth; but with these two exceptions, it can do anything the heavy force can do. Unfortunately, the immense politico-economic value Federal German territory has now acquired in NATO eyes deprives the Alliance of the ability to trade off real estate for attrition and time to anything like the extent that maneuver theory requires. The post-1973 Bundeswehr is committed to a forward positional defense, with maneuver limited to the middle tactical levels. This constrains the American and British forces to adopt a lattice-type defense, with firmly held strongpoints at the nodes of the lattice (active defense), and with robust if less enduring anvils of various sues (active defense and AirLand Battle). The nodes of a lattice defence are evidently no place for light forces; if forced back, they can neither maneuver on open ground, nor counterattack, in face of a full-scale assault led or supported by MBTs. Similarly, in view of the mass of the attack facing them, anvils composed of light forces may not be robust enough to set up the attacker for the hammer blows. In positional defense, or in the positional component of a mixed defense, the best use of light forces, mechanized and dismounted alike, is in the economy of force role. Until the early,608, the US. Army, like most others, employed lightish but fairly powerful cavalry units as a forward screen or covering force, as well as for reconnaissance in the strict sense of gathering information. Then, as mentioned earlier, the US. Army decided to assign battalion combat teams from the main maneuver force to the screedcover-ing force role. Whatever the reasons for this decision, and however high some Allied eyebrows were raised when they learned of it, I suggest it was and still is a tactically sound one in the particular circumstances of the NATO center. Like other components of the defense, even more so maybe, the covering force has to I gain a lot of time at the cost of very little space. To do this, it must certainly be able to stand and to maneuver in the open, and it may have to make short, sharp counterthrusts against advancing tank formations. It, therefore, itself needs MBTs. I have not seen the phrase “anvil and triple hammer” in black and white. But if one reads the AirLand Battle as an evolution of active defense and sees AirLand Battle and strike deep as complementary, the concept as a whole calls for three kinds of hammer. The first is a low-level tactical hammer, probably formed by the anvil’s tactical reserve. This delivers a short blow under cover of direct fire support from the anvil and of artillery fire controlled by observers within the anvil. If, for example, the anvil was based on a defile, this blow might consist of a tank-heavy battalion combat team launched into the mouth of the defile to isolate the emerging vanguard and nip deployment of the second advance guard battalion in the bud. In terms of maneuver theory, this is essentially a tactical maneuver within the holding force (main force), and calls for the striking power conferred by MBTs. The higher tactical hammer - the classical one - is normally launched from a secure area behind the anvil onto the flank and/or rear of the enemy-formation, say a division, that has been set up by the anvil. In heavy force terms, this hammer might consist of a tank-heavy brigade-level task force, supporting or supported by a suitable task force from the ACAB. Although still at tactical level, this more far-reaching blow is a mobile force action in terms of maneuver theory. The key to success is momentum achieved by high tempo. If it moves fast enough, the only deployed force this higher tactical hammer should expect to face is the enemy flank screen. Provided it penetrates this quickly, the enemy main bodies will have neither time nor space to deploy. Here the higher tempo of alight mechanized force should more than offset its limited firepower and direct protection. What is more, this higher tempo bridges the very uncomfortable mobility gap between the heavy track and the rotary wing, thus allowing the helicopter force to operate to greater effect and at less risk. Of greater importance still, though, is the operational hammer of the follow-up force attack (FUFA), d e signed to strike into the windows between enemy echelons created by the air and long-range artillery interdiction strike deep. This could conceivably be executed by a rotary-wing force of one or more ACABs acting at operational level. But at the present stage in the rotary-wing story, one has to ask the question: “What do they do when they get there?” The Soviets -may well be right in their caution about operational employment of their rotary wing airborne assault brigade, and in their insistence on a land followup within six hours. The arguments deployed in the preceding paragraph gain still more force here. A heavy division reinforced by alight mechanized brigade to spearhead the advance and link up with the ACAB would seem ideal. In a major counterstroke, say a corps-level offensive, the role of light mechanized forces would be threefold (and what followsis based rather closely on Soviet thinking about BMP-based forces). Initially their role would be to open up a penetration by a slashing attack if a weak spot (a boundary for instance) or a gap can be found. The light force is inserted and follows the line of least resistance to the defender’s divisional or (depending on his density) army rear boundary; it turns in along this lateral until it reaches a potential primary axis and advances down this. The heavier component of the mobile force follows as close on its heels as it can, peeling off combat teams (Soviet raid forces or air-ground assault groups) to deal with gun lines and C3 nodes. In sum, positional warfare, or the heavy break-in phase of an offensive, relegates light mechanized troops to an economy of force role. They cannot and should not mix it with the big boys within the confines of a ring. By contrast, once mechanized manuever warfare offers free play, these troops become a significant military asset and can 40 play a leading role in both senses. Their value is further enhanced in an airmechanized scenario with higher tactical and operational actions by rotary-wing formations. Light Mechanized Forces in Intervention There will be many cases where intervention is desirable or necessary but the METT-T conditions rule out the use of light mechanized forces. The different types and balances of force required are a further argument for a brigade-based structure. At the other extreme, there are theaters and situations where mission and terrain call for mechanized forces but the mechanized and antiarmor threat is minimal or absent. Here alight mechanized battalion combat team (figure l), maybe minus one or both of its antiarmor support companies (LMPG, LTV) could dominate the situation and do pretty well as it pleased. Even a company combat team of this kind might be decisive. As a rule, though, the intervention will face an opposition with American, European, or Soviet heavy e- quipment, including MBTs, no more than a half-generation out of date. No intervention force operating at the end of its air lines could hope to defeat such an enemy in positional warfare. Allowing him to adopt a posture of positional defense puts minimal pressure on his weak points - command, staff and logistic skills, and ability to maintain his heavy equipment. Given a firm base (presumably round the airhead) and logistic sufficiency, a rotary-wingAight-mechanized force can sally forth, dislocate the enemy by swift and sweeping operational maneuver, and destroy him in detail if needs be. I doubt I need enlarge on this concept for ARMOR’S readership. But, despite its ability to put a reasonable number of men in foxholes if needs be, the light mechanized force is not exactly manpower-intensive; and a rotary-wing attack/ assault force is even less so. On the other hand, both strategic and operational/tactical airlifting of standard and airborne infantry is a massive business. (Just to drive this point home (using 1984 figures), the U. S. airborne division is over 18,000 strong, requires a lift of 1,111 C141Bs, and puts 4,100 men in foxholes), the light infantry division (7th ID model) packs just over 10,100 men into 461 Starlifters and puts 3,400 of them in foxholes.) The light mechanized force must therefore be balanced by a truly light infantry force to secure a forward base, to deal with downtown urban terrain and impassable terrain, and/or to take out any guerilla threat by the roots. In yet another type of situation, alight mechanized force may be called on to operate in support of airborne or standard infantry against an enemy with MBTs. This is extremely dangerous unless the infantry commander himself understands the strengths and weaknesses of light armored vehicles or listens closely to the mechanized commander, now his advisor. In terms of figure 1, the key mechanical elements in the defense now become the TOW and mortar companies, reinforcing the infantry’sown. The LMPG company could be grouped with an infantry battalion for attack, provided that the LMPGs are not asked to lead and can therefore make use of cover from fire. The light mechanized companies must not be employed in frontal attack. They could be used in a dismounted positional defense with their vehicles in support, much on the line of current Panzergrenadier thinking. Or, if there is - as there may well be, an open flank, they can carry out a harassing or turning role. Conclusion If the U. S. h y wants alight mechanized force, it will need to structure, equip and train one virtually from scratch, basing it in some way or other on integrated armor-infantry units. The decision against an integrated combat arm for the 1986 force structure suggests that this might give rise to serious cultural shock. A whole family of equipment would have to be developed, this in an area that is historically not the U. S’s. strongest. This would divert much talent and money from the heavy maneuver force programs. The development of doctrine and subsequent training would add to the problems of multiplicity of role that are already making armor and infantry scratch their heads. Opponents can and do argue that no other advanced army, except maybe the French, has such a force. Yet no other advanced nation, except maybe France, has the strategic need to intervene militarily at the end of long air lines, backed by the political will to do so. The switch to operational and tactical doctrines based on maneuver theory, coupled with the employment of air cavalry at operational level, makes alight mechanized element a clearcut military asset in the heavy maneuver force setting - maybe an essential rung in the mobility ladder. At the same time, both the strategic need for effective intervention and the political will for it are on the up and up in the U. S. These factors argue for a force of one light mechanized brigade per 1986 type A Heavy Division, distributed in peacetime between CONUS and 7 (US.) Army. One of these four brigades could be deployed as part of a rapid intervention force; or they would be speedily concentrated in Europe. In the short term, there looks to be a case worth examining. In the long haul, a force based on the rotor and the fast track is thevehicleneeded to carry thought and reality from the baroque blud-geons of the present to the hi-tech rapiers of the future.

BRIGADIER RICHARD E.

SIMPKIN had an extensive responsibility for arrnored vehicle development during his long career with the British Army, including the Chieftain, Scorpion, and Anglo-German MBT programs. In retirement, he manages a language consultancy and is the author of several books, including the recently - p u b I i shed Red Armour. ARMOR 41