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The widespread understanding of tanks is likely outdated because there has been only a rather limited set of experiences post-'45. Lean back and enjoy some thoughts of mine; I attempt to substitute for our lacking military history experience with my brain power and knowledge about military equipment.
I am of course in a hopeless situation as an under-resourced individual here, but the stuff might still be relevant to your interests.
The established idea is that tanks are no good in terrain with short lines of sight.
The tank crews' weapons out-range infantry weapons (a) and thus they're better off in open terrain. Even man-portable infantry weapons have been a deadly threat to tank crews since 1943 (b).
Tanks need to have some spacing in order to mitigate indirect fire effect with dispersion (c) and in order to insure themselves a bit against surprise contacts. The spacing is more practical on open ground where platoon and company leaders can still see their tanks (d).
A buttoned up (hatches closed) tank crew has typically a poor all-round vision (e). Infantry can sneak up and employ even Molotov cocktails and improvised explosives against such a partially blinded and deaf tank crew.
Open ground is also typically less riddled with obstacles that are relevant to a tanks' mobility. A tank can drive through a tree or a house, but it's not recommended standard practice.
Thus, tank crews learned to avoid areas with short lines of sight unless they really need to enter them.
It was nevertheless understood since the 70's that tanks are also terribly exposed to hostile long-range weapons on open ground. The open ground became the favourable terrain for attack movements when the opposition was blinded or suppressed, but cluttered ground was understood to be favourable for hiding and ambushing.
Let's look at some changes in military technology next:
(a) Infantry became equipped with sophisticated guided anti-tank missiles of 2,000 m range. This enables them to shoot at tanks at practically every relevant distance whenever there's even a choice between close and open terrain.
(b) Man-portable anti-tank weapons are based on the shaped charge principle - the armour penetration principle that can be defeated more easily than all others. Tanks have been optimized for tank vs. tank fighting for decades, as tanks were the greatest tank killers in WW2 and in the Arab-Israeli Wars of '67 and '73. This narrow optimization lead to an extremely strong frontal armour (glacis, turret front) and as a compromise poorly protected sides and rear.
The lack of serious opposing force tanks after the Cold War has led to a different compromise, though: Upgraded and new tank designs are now meant to resist man-portable anti-tank weapons all-around.
These very same man-portable AT weapons have also increased in range. A Panzerfaust 60 of 1944 had 60 m effective range, a Panzerfaust 3-T600 has 600 m effective range. The increased range makes it ever more difficult to avoid their firing envelope. Much of this increase (about the jump from 300 m to 600 m) happened in the 90's when computerized sights with laser range finders gave the infantry high-quality fire control aids for their heavier man-portable anti-tank weapons.
(c) The indirect fire attack of choice against tanks isn't any more a concentration of hundreds of bomblet shells and rockets. Modern artillery turned towards precision munitions and seeks direct hits. Dispersion doesn't mitigate such a threat any more.
In fact, dispersion might add to the tank's vulnerability because it's more difficult to maintain a large multi-spectral smoke wall than a small one. Dispersion might at times force tanks into poorly concealed positions, while at other times concentration might do the same. Overall, recent developments have added a question mark to the value of dispersion.It became a more situation-dependent method than ever before.
(d) Many modern tanks have a Blue Force Tracker or similar system. Such a system can show the location of every unit, small unit or team on a screen and can be updated in short intervals. A well-designed system of this kind can offer a unit leader an accurate and up-to-date overview about the positioning of his teams as long as radio traffic is permitted and possible. A tank company leader doesn't need to maintain a line-of-sight to all his platoons and tanks to know where they are - not any more.
(e) They have been possible for decades and are slowly being added to modern tanks: All-round camera systems for tanks. The Merkava 4 tank has such a system; the commander knows about the surroundings of his tank and eventually he would also know about nearby hostile infantry. This awareness is now independent of whether he's buttoned up or not (as long as the system works).
This begs a central question: Is close terrain really still a tank-unfriendly type of terrain? Is cover and concealment for infantry within infantry arms range really a problem any more?
Maybe it's not. Close terrain offers many advantages to a tank as well. These advantages have merely been overshadowed by the perceived disadvantages during the last decades.
The short lines of sight offer the element of surprise to a tank and they allow for a quick withdrawal. The enemy in LOS is isolated from most of his comrades because of the short lines of sight. An attacking tank company that bunches up and fights its way through a short line of sight terrain could dominate the local fight with its superior concentration of fighting power and its superior protection. It could also exploit the short lines of sight in order to mitigate hostile support fires simply by keeping its exposure to any one hostile position too short for a proper indirect fires mission.
Maybe we should think less in terms of line of sight than in terms of density of obstacles to movement. A terrain with long lines of sight yet very little terrain that tanks can negotiate (such as in the high Alps or in the Pripyet Swamps) is no tank-friendly terrain. The LOS is irrelevant here.
Likewise, a quite obstacle-free terrain with much concealment (such as a wood with many young trees and bushes) for a LOS of only a few hundred metres at most might actually be excellent terrain for tank crews if these tanks are properly equipped.
Is this correct? I don't know. I have no idea. I have no idea because there was no real test for it.
This is -again- a topic where it becomes ever more obvious that we don't know how to fight under modern battlefield conditions against a first rate opponent. Exercises on training grounds don't provide a satisfactory answer. Neither do the rather anecdotal combat experiences in the wars after 1945.
We might be up for some really, really terrible surprises in the next major war.
S O
P.S.: You might be irritated by the possible conclusion that long LOS battlefield terrains are probably poor for everyone - infantry and armour alike. This should be a non-surprise given that I have long advocated that exposing yourself is getting you killed on a modern battlefield. I just applied
this more to infantry than to armour so far.
edit:
I forgot to mention: The ability to negotiate obstacles gains importance once obstacles become the decisive tactical restraint. This means that fully tracked vehicles with good trench crossing ability, good power/weight ratio, low mean maximum ground pressure and possibly a dozer blade would completely outperform any of those fashionable 8x8 vehicles and probably also 55+ metric ton tanks.
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