Combined arms is an ancient concept. In this context, it refers to the presumed ability of infantry which accompany tanks to protect them from man-portable antitank weapons. This was feasible when man-portable antitank weapons were unguided and extremely limited in effective range – 50% hit — of no more than a few hundred meters. Working in concert with the tank, an exclusion zone keeps these weapons out of range.
Although (pdf) Mathematical Analysis of the Counterfire Duel: Tanks vs. Anti-Tank Munitions is specific to the M712 Copperhead, it is representative of smart munitions in general:
Abstract-A detailed, analytic model is developed to represent the duel between a ground laser designator (GLD) directing a sequence of laser-guided rounds against a platoon of target tanks which counterfire against the GLD. The model accurately portrays the complex interplay between the designator-on time, the rate of fire of the laser-guided rounds, and the tank counterfire response time distributions. Also taken into account are the tank aiming errors and range estimating techniques. the level of GLD protection, flight times, designation modes, and degree of coordination of the tank platoon.
Before the advent of a whole class of precision weapons with strong analogy to the above, it took bravery to confront a tank at close range. The need for bravery has been reduced to a level less akin to immediate self sacrifice.
Skip to page 40, figure 13. Quoting,
The graph shows the expected number of tanks killed (solid curves) and the probability of GLD kill (dashed curves) in a 3-on-3 encounter over a range of tank-to-GLD distances,with the GLD located in either a foxhole, a Forward Observer Vehicle or a bunker.
The greater the distance from the GLD to the target, the more kills achieved by the GLD before it is destroyed. This is the opposite of unguided man-portable antitank weapons. The required exclusion buffer around the tank expands to 800 meters for the NLAW, 4000 meters for the FGM-148 Javelin, and 8000 meters for the 9M133 Kornet. It is not possible for infantry to exclude these weapons from large areas that they do not yet control.
Penetration of Russian tank armor often results in ammo cook-offs resulting in the jack-in-the-box blown off turrets. Tank proponents vaunt the superior armor and ammunition storage of current western main battle tanks, which do not so dramatically destruct. Sadly, drama is not required. A hit from a top attack weapon has a high chance of penetration, almost inevitably causing multiple crew casualties, disabling the tank.
While the Abrams and Leopard 2 have clear advantage over Russian tanks in frontal engagement, this does not imply greater resistance against top-attack weapons, or from attack from the sides or rear with shaped charges or explosively formed penetrators. While crew are more likely to survive a penetration, the result is 60-70 tons of metal transformed into spare parts and scrap.
The Marines have turned in their tanks, mandated by their new littoral mission. A general principle can be distilled: Stealth multiplies lethality. Is it impossible to employ armored spearheads in Ukraine? If the abysmal performance of the Russian army continues, it is conceivable, though such assumption receives warning from von Clausewitz. Paraphrasing, the enemy does not do what you want him to do; he does what he wants to do, which could be competence with the 9M133 Kornet. Cluster munitions would be far more useful to Ukraine.
This is a plausibility argument, not contradicted by recent battle experience. We guessed this war all wrong, which does not hinder tank proponents, yet should give pause. The tentative conclusion is that the current battle doctrine of combined infantry-armor requires either re-validation or revision.
For those readers who desire a short summation of this complicated discussion, here it is:
***Tanks are NFG***