Shares of a division

Here's a quote form Dunnigan's old book "How to Make War" (2003, p. 124)  that - while old - still largely applies:

Depending on the type of division and nationality, infantry comprises 8-30 percent of division strength, tank crews 1-10 percent, and artillery (including antiaircraft and antitank weapons) 6-12 percent. Combat troops comprise an even smaller potion of non-divisional forces, something like 5-10 percent. Since combat divisions account for 20-50 percent of army manpower, combat troops comprise only 10-25 percent of all personnel. In all armies, combat support troops are very much the majority.

Elsewhere he wrote that infantry comprises about 5 percent of a Western army's personnel strength only.

There was a move away from division-centric to brigade-centric force structures since, but the overall picture remained about the same. Thus let's take Dunnigan's summary above as a basis for some thoughts:

Some support efforts have a fixed size (equivalent to fixed costs in economics); area air defence by a SAMP/T battery does not scale with the combat troops in the shielded area, except that it is either provided or not. Bridging requires about the same effort, regardless of whether one or ten tank battalions are going to cross that bridge. Load carrying capacity (MLC 60, MLC 80 etc.) doesn't affect personnel demands much either. The width of a bridged river on the other hand changes personnel requirements slightly (more pontoons = more lorries to carry them = more engineers for driving and installation). Electronic warfare is similar; either you have those jammers to blind a JSTARS-like aircraft 300 km away or you don't. Either you have the receivers in position to triangulate radios in the area or you don't - there's no proportionality with the quantity of combat troops in the area.

_ _ _ _ _

A look at tooth to tail ratio or a listing of percentages as Dunnigan provided implies a relationship between combat troops and combat support (fashionably: "sustainment") troops that's following a stable causality. Now I pointed out that sometimes the terrain features instead of the combat troops are the influencing variables. Long-time readers of D&F may probably sense where this is heading:

The 'book' needs to be rewritten and reconsidered for low force densities in state vs. state or alliance vs. alliance (a.k.a. "conventional") warfare.

A 100 x 100 km area may see (among other forces) five manoeuvre battalions, one area air defence battery, one independent bridging company, one field hospital with MedEvac helicopters, one battery with 100 km range artillery missiles and one jammer against radar aircraft.
What happens with the support elements if there's but one brigade in action in the area? Will there be the same amount of one-or-nothing support elements or none? Does this problem lead to an even smaller share of combat personnel in an army or to the opposite, a cutting down of combat (service) support of the one-or-nothing nature?

Second challenge; what about small allied powers' contributions? They do likely not (and should not) have the same assumed-to-be optimal structure in miniature. Shouldn't the larger armies with focus on collective defence compensate for this by having even more than optimal shares of support troops in order to reach the optimal mix in a collective deterrence and defence effort?

Another challenge; with only 10% combat troops an opposing force needs to cause less than 5% casualties to break all of our ground forces and to force them into a general retreat. Maybe 2% if the offensive is limited to one region. We sure need to have personnel reserves for the refreshing (refilling) of combat units, but (assuming these reserves are not in the support units) why wouldn't we employ these reserves right from the start if this leads to a less than proportional growth of support requirements, in low force density scenarios more pronounced than in a long time?

In the end I advocate a close look at the optimum mix for low force density scenarios, while keeping in mind that over time the arrival of reinforcements (even from different countries) will change the structure and the force density in the theatre of war - and thus also the optimum structure.

There's a pretty strong case for thorough research, experimentation and alliance-wide coordination in order to avoid wasteful spending and a waste of the soldiers' time with surplus capacities.



  1. For any small country the no 1 priority is deciding not to follow the US army. The US army structure allows it to rotate units in and out of theater, and function on a very long logistic string.

    So you don't need to have mini divisions as brigades, and you don't need either the divisional or corps level.

    No 2 priority is fight the HQs. The HQs are sapping away at the tooth strength since WW2. Don't use HQ companies that have communication and logistics attached. That way the bureaucracy obfuscates the number of officer spots it creates out of nothing.

    Consider if you need the brigade level. Small countries might be better served with a division/corps HQ/ that has LR/Area artillery, Area AA, military intelligence and police and engineering assets plus 5-10 battalion+ groups.
    While completely useless for foreign expeditions, such a force has a lot more fighting troops.

  2. regarding your 2 priorities madner. logistics whether short or long is a priority. no logistics is not an option. second comms not attached to HQ???? effective rapid communication from/between the various units (eg front line infantry and artillery/air support) is 9/10, the difference between success and failure in a military operation. small countries would be best served by small units formed from local citizens that know the area the fighting is occurring in and have effective and secure communication to HQ that can co ordinate the units from an overall perspective of the battle(s). artillery and non portable aa would be eliminated by air or missile strikes (if fighting a larger country).

    1. I think he meant that signal troops should not be part of HQs so the size of the real HQ operation becomes visible. This is about OOB, not about actual employment.

      It's questionable whether self-propelled AD or arty would really be eliminated by land forces of for example the Russian army's sophistication. See MICA VL, IRIS-T SL air defence or the artillery shoot&scoot ability (with SPGs dispersed instead of in battery formation as before land navigation became electronics-based).

  3. You can have the same amount of signal forces if needed, but as a separate squad/section/platoon.

    You can have the same logistic units, but again in a separate platoon / company.

    Right now the largest company in most western battalions is the HHQ company. Which means that the 8 largest companies in a US style brigade are HHQ (brigade HHQ and the 7 HHQ companies)

    Logistic demands to operate a heavy force 500 km from the nearest friendly source and logistics to operate a medium force within the country are not the same. This determinates how many supply "brigades" you need.

    Logistic and transport units should be attachable to those battalion battle-groups.

    Some numbers from Other end of the Spear:

    1968 the US army in Vietnam had 305 000 troops. Of those 72500 were logistic troops, 39500 life support and 92500 HQ troops. (combat troops 100 000, all a bit rounded up or down).

    In a stryker brigade (heavy on rifles), out of 4800 men, 840 are HQ troops.

    Artillery, AD and tanks should be part of each Bat+. Even if the opponent can eliminate it, the threat of Bat+ the on the flank is much more serious that way. Whether it should be SP or towed, depends on the terrain.

  4. A higher percentage of true light infantry means fewer support troops because the logistical footprint of such infantry is much smaller. It also need fewer combat support troops (like pioneers etc). And in a professional army a soldier always costs the same pay - regardless if he is a professional light infantry or a support troop.

    So increasing the percentage of professional light infantry in a division / brigade means automatically a higher percentage of combat troops and fewer support troops.

    They are moreover cheaper because of their cheap equipment and in an alliance poorer countries could offer such troops in higher numbers in comparison to mechanised / heavy troops. They are no offensiv thread (i believe that deterrence is good, but their can be to much aggressive/offensive deterrence that can even lead to war), easy to move strategically, especially good in COIN / Ocupation / Hybrid Warfare and therefore i strongly suggest to increase the percentage of professional light infantry in the western armies and in an alliance the poorer (frontier countries of eastern europe) should specalise in such troops. A unified proffessionl light infantry of such countries would also exploit the advantage of the much smaller payment in this countries - and in an alliance military aid of richer countries could then lead to an size of the forces much higher than this smaller and poorer countries could maintain for themselves.

    To the opposite all of such countries now purchase mechanised forces with wheeled infanry fighting vehicles, sp heavy artillery and so on.

  5. I think an important step for a primarily homeland-based global intervention-oriented kinetic force would be to stop thinking in 18th century unit sizes and C2 schemes. When you plan to defend against a known enemy in a known territory things are easiest. When you plan to attack a known enemy in a known territory things already become more complicated (one can only wonder how the Wehrmacht managed). And the most difficult is planning to attack a variable "someone" in a variable territory. The last case requires so much flexibility, modularity, scalability of forces that a traditional setup is useless, and a "cloud" forces approach must be taken. Works only with a lot of training and very flat structures. The other options are permanently forward based field armies in the most likely theatres of war fighting, or regional vassals who do the ground war job and are supported by stand-off kinetic and non-kinetic/hybrid elements of Empire troops. Currently the Empire uses a mixed approach that's not really effective on the ground and very expensive.