Army defense tactics question

From what I understood about defense, which is very little, usually you have for example 2 brigades on the front and 1 brigade in the back (in the 2 echelon defense) and that ,2 in the front, one in the back" pattern is showing up from small units like platoons all the way to corps and so on, so basically when the enemy breaks the gap, the 2nd echelon unit is supposed to stop him and close the gap. I don’t understand however what happens when you have 2 bigger units (composed of 6 smaller units) and have those 2 units next to each other. They both have the 2.nd echelon unit to defend the gap between the 2 units in the front, but what about the gap between the 2 bordering front units of 2 bordering bigger units? Here’s an example, unfortunately this is in Russian, but its a simple drawing, so its not important, its a drawing of a battalion in defense, the 3 large things (мср) are companies http://army.armor.kiev.ua/tactik/msb_oboron.gif and the 3.rd one in the back obviously defends the gap between the first two companies, but what about the area behind the company in the right from this battalion and the company on the left from a battalion that is next to it, who is defending that area?

The gap between 1 Company and 2 Company isn’t being held by 3 Company, it’s being held by the firepower of the right flank of 1 Company and the left flank of 2 Company. It being in Russian does make this a bit trickier not knowing what anything says, but one might be that the drawing is not to scale. You’ll notice the distance between 1 and 2 Company is 1km, while the distance between 3 Company and the front line is 2km. Again not knowing for sure what this drawing says or exactly what it’s meant to represent, I’m assuming that 1) it’s for modern armored forces, where a ‘gap’ of 1km isn’t really a gap as modern anti-armor weaponry is effective at ranges far in excess of 1km and 2) it’s for a battalion in hasty defense as opposed to one that’s assumed a posture of deliberate defense. 3 Company is positioned to act as a reserve and is able to move from its current position to reinforce, counterattack, or maneuver against the enemy in response to their actions more than it is positioned with the intention to only defend in place.

Regimental reserves. There’s always a “next level up” until you get to divisions and corps, and even they have reserves waiting to leap into a breach.

The real danger (in WWII) – as in Stalingrad and Bulge – is “lightly defended areas.” Stalingrad’s flanks were held by under-strength German allies, and the front of the Bulge was a “rest area” for tired-out units.

I can’t view the image file in question, but I’ll submit a general point: The idea is not to create an unbroken wall of troops. Further, in modern warfare even a company of troops is a lot of firepower. A lot of it depends on what they are trying to accomplish. For example, if the defense is trying to prevent movement along a road, all they need to do is set up a position where they can place firepower on the road… This doesn’t imply that they have to physically barricade the road with wall of soldiers.

Further, defensive positions in modern war are 360 degrees. Each individual fighting position will be assigned a “sector” to cover, much like slicing up a pie. The commander will tell them, (for example) Squad One takes the 12 o’clock to one o’clock position, squad two takes one o’clock to two o’clock, and so on. The responsibilities are divided up until every direction is covered.

Also, keep in mind what you are really seeing when you look at one of those diagrams. Usually they are pretty abstract. If a company sized element is located on a 1km grid square, they might all gather at a single camp or obstacle, or that might be a square kilometer in which squads and platoons are scattered like little islands.

Here’s the same picture, but with the entire article, maybe this link will work for more people http://army.armor.kiev.ua/tactik/msb_oborona.shtml , anyway I forgot to mention that the 3 red lines represent trenches (if that changes anything, so this is supposed to represent a deliberate defense, not a hasty one) , the 3 things inside the companies are 3 platoons and apparently they also have the same 2 in front, 1 in back position, the до 1км or до 2км text means ,up to __km" , so the gap between the 2 companies in the front can be up to 1km and the distance of the 3.rd one in the back is up to 2 kilometers. The thing in the front is a company doing a security mission.

Here’s another image, this one is a little more informative http://www.globalsecurity.org/military/library/policy/army/fm/71-2/fig3-11.gif and it is from here http://www.globalsecurity.org/military/library/policy/army/fm/71-2/Ch3.htm , it kinda explains what happens in the ,gap" , but again it is unclear on what happens between the sides of the 2 battalions

In traditional infantry (foot, vehicular, or even cavalry) tactics there is always a seam between units. And in the situation of prepared defense that seam is a place of increased risk. If the enemy does start a breakthrough there the coordination of defensive response is incrementally more difficult.

As such the defenders will do things to ameliorate that incremental risk. Such as :

  1. Have the next-echelon commander pre-decide which 2nd echelon unit has primary responsibility for that gap. Ensure communications are set up to make calling for that help easy & direct.
  2. Spread the 2nd echelon unit geographically so it’s better able to respond to the inter-unit gap it’s responsible for as well as its intra-unit gap.
  3. Set the frontline units up so those seams are in more difficult terrain, or areas better swept by direct fires or artillery.
  4. Concentrate static defensive measures like mines, barricades, wires, etc. to canalize the enemy thrust elsewhere.

One of the key things when you see a traditional army topo map with the little unit symbols scattered about is to recognize that the units aren’t actually deployed under the footprint of that icon. The icon represents either the HQ location, or a general centroid of mass of the unit. And the bigger the unit, the more this is true. A modern first world infantry platoon in permissive terrain may control a half-mile square and influence a full mile square. Despite being only 2 truckloads of men who would all fit in my house & driveway.

The icon is not the unit is not the terrain they control is not the terrain they influence.

First it’s important to remember that battles don’t usually happen on pool tables. (Even battles on very flat spaces can be affected significantly by relatively small terrain changes.) That layout is pretty basic for a fight on a pool table. It’s also important to realize that not all defense is positional and even more positionally organized defenses can involve mobile aspects and planned counterattacks to the overall scheme. That before we even get to considering the security zone fight forward to the main defensive area that sets the stage. (One of the old lessons from direct action style scenarios at the NTC is the winner of the counterrecon battle usually wins the overall fight.)

All that said:

  • That gap isn’t a gap in pool table land. Just off the top of my head some ranges for a couple old Motor Rifle Company weapons - AT-5 4,000 meters, PK(M) medium machine gun 1000 meters. There’s significant overlap in fires. Outside of Pooltablelandia there can be gaps or covered avenues of approach that have nothing to do with that spacing.
  • Gaps are things that can be made during the fight. That element to the rear provides depth (with fires that control a good chunk of the area behind both up front units.) That first local penetration isn’t necessarily the end of the positional defense if some of the attacker breaks through.
  • Aside from a positional depth, that unit behind can function as a reserve. It can be used to reinforce parts of the defense that are in danger of giving way or counterattack to retake key terrain, finish the defeat of the attacker, or even set the stage for an overall transition to offensive operations.

The two most important things to take from that layout in my formerly professional opinion are the words I bolded above - depth and reserve. Both are important concepts for successful defenses.

Thanks everyone, just one more question that is kinda related, when you are overstretching do you use the one echelon defense? As an example here is the Serbian side in Bosnian war (red color) https://upload.wikimedia.org/wikipedia/commons/thumb/0/0a/BeforeDayton.png/793px-BeforeDayton.png , they had by different sources from 80 to 100 thousand soldiers, not sure how many brigades, but usually Yugoslav brigades were around 2500 people, so that would mean around 40 brigades (except the fact that usually they weren’t 100% filled, but for the sake of the question let’s assume they were) and the front was around 500 kilometers, 500/40 is 12.5, so that means that each brigade defended around 12 kilometers, right?

In response to your first question, the previous answers are correct- the only thing I didn’t see mentioned is that the diagram is likely a doctrinal picture showing how to defend with only MTOE troops, but the defender may very well have attachments to fill the seam. Maybe an AT Company that they split up on each seam and hold a platoon in reserve.

That reminds me of Napoleonic warfare where the light cavalry composing the screen/recon of one side would engage its counterpart. Could you go on about that the importance of recon/counterrecon? Were the scenarios you participated in mainly meeting engagements between units composed of mechanized infantry and armor?

What would be the equivalent for a successful offense?

In the Bosnian war, the Serbian side wasn’t defending much, it was attacking and besieging a much inferior force.

Whether one would use one or two echelons would (among other factors) depend on the enemy. The more mobility your enemy has, the more having a second echelon for your defense matters. You might even let the enemy penetrate your defenses:

"Blitzkrieg is vulnerable to an enemy that is robust enough to weather the shock of the attack and that does not panic at the idea of enemy formations in its rear area. This is especially true if the attacking formation lacks the reserve to keep funneling forces into the spearhead, or lacks the mobility to provide infantry, artillery and supplies into the attack. If the defender can hold the shoulders of the breach they will have the opportunity to counter-attack into the flank of the attacker, potentially cutting off the van as happened to Kampfgruppe Peiper in the Ardennes.

During the Battle of France in 1940, the 4th Armoured Division (Major-General Charles de Gaulle) and elements of the 1st Army Tank Brigade (British Expeditionary Force) made probing attacks on the German flank, pushing into the rear of the advancing armoured columns at times. This may have been a reason for Hitler to call a halt to the German advance. Those attacks combined with Maxime Weygand’s Hedgehog tactic would become the major basis for responding to blitzkrieg attacks in the future: deployment in depth, permitting enemy or “shoulders” of a penetration was essential to channeling the enemy attack, and artillery, properly employed at the shoulders, could take a heavy toll of attackers. While Allied forces in 1940 lacked the experience to successfully develop these strategies, resulting in France’s capitulation with heavy losses, they characterized later Allied operations. At the Battle of Kursk the Red Army employed a combination of defense in great depth, extensive minefields, and tenacious defense of breakthrough shoulders. In this way they depleted German combat power even as German forces advanced.[citation needed] The reverse can be seen in the Russian summer offensive of 1944. German attempts to weather the storm and fight out of encirclements failed due to the Russian ability to continue to feed armoured units into the attack, maintaining the mobility and strength of the offensive, arriving in force deep in the rear areas, faster than the Germans could regroup and resulted in the destruction of Army Group Center in Operation Bagration."

In some ways, blitzkrieg is analogous to HEAT warheads and defense in depth is analogous to spaced armor or Chobham.

When using the hedgehog defense, I’m not sure it even makes sense to think in terms of 1st and 2nd echelons:

Most likely combined arms attack. The idea is that it is relatively easy for an enemy to defend against any single mode of attack, if they know what is coming. Therefore, the goal of the modern attacker is to place as many different weapon systems on the target as possible. Infantry, armor, artillery, and close air support should all be striking the target simultaneously so that it is impossible for them to defend against any one threat.

In this mode of attack, success will most likely go to the leader who is best able to coordinate each different asset to act in concert. If the attackers become disorganized, delays result and the attacks land in uncoordinated fashion. If this occurs, the attacker is more likely to fail.