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I was working on a rather specific text on infantry (a strangely attractive topic) when I realised that the whole thing needs more context. Thus context first:
(As I see it:) Waves in combat techniques / art since about Napoleonic times, descriptive of best practices only:
Offence 1st wave
Early on (up to mid-19th century), offence took the shape of troops closing in with the enemy in close order formations.
Defence 1st wave
During the same period, infantry and artillery defence took the shape of troops still being upright and on ground level, giving their best to break up the attack with their firepower. Cavalry was an exception, as attack proved stronger, not weaker for cavalry. Defending cavalry was thus either luring pursuers into a trap or counter-attacking itself.
Defence 2nd wave
Firepower had grown due to spin stabilised bullets, and the (fixed) defenders adapted by making more often use of field fortifications (trenches). This began during the mid 19th century and was perfected by about 1917 when only a small share of an army held the front line with main resistance line being kilometres in the rear, more difficult to reach for enemy artillery..
Offence 2nd wave
Firepower affected the exposed attackers a lot, so they had to adapt, too. Artillery adapted first by switching to indirect fires. This gave the attacking artillery the survivability to bring its weight into battle - soon (by 1915) it played a major role in creating gaps in the defender's lines.
Infantry had to adapt on the offensive (by 1916) by avoiding fields of fire as much as possible; the exploitation of micro terrain for cover and concealment became standard instead of an exception.
Tanks were another contribution to offence as their armour allowed them to keep moving and fighting under fire even (and especially) on an open field.
Offence and defence 3rd wave
1944 carpet bombing and incredible artillery concentrations (naval gunfire at Normandy, 44/45 Red Army breakthrough concentrations of artillery) were early indicators, but tactical nukes made it obvious to anyone: No high force density defence could really withstand a focused attack, no matter how well it was dug in.
Even temporary field fortifications in mobile warfare had lost much of their value, since techniques and technical equipment for effective indirect fire support for mobile forces had been introduced and highly mobile armour units with lots of high explosive firepower were able to appear almost everywhere.
This did not seem to affect Cold War military theory much, since there weren't enough troops for continuous front lines even in Central Europe anyway (26+ divisions only on a 1,000+ km frontier). Tanks had become operationally mobile by the 1930's and Cold War offensive thinking was very much coined by mobile warfare ideas. Corps would still form a front line on a war theatre map, but many of their brigades (the 'heavy' ones) would behave more like 18th century battle cavalry, preferring offence over defence.
Defence theory reached its peak for small units, but to late; stationary defence was reduced to the (small) unit level; formations in static positions would be overwhelmed by firepower or simply be bypassed by advancing opposing forces.
Offence 4th wave
Guided weapons, increased accuracy and responsiveness of attacks with non-guided munitions and a major increase in technical sensor capability lead to a (often-criticised) attitude reminiscent of 1915-1916; firepower would pave the way by knocking out who got detected. Detection, not destruction of the enemy, became the primary difficulty for the offence.
Defence 4th wave
Defence looks in theory still a lot like during WW2; even some well-reputed armies never fully mastered defensive techniques, and more importantly, didn't delete defensive techniques from their manuals even if they're already obsolete against a state of the art offence.
Both armour and field fortifications are already largely devalued as tools of defence. The modern defence against modern attacks struggles to defeat the offence's critical strength; the ability to find, identify and allocate and targets (=defenders) in time.
There's a modern response to this challenge which has surprisingly old roots.
Nowadays, there exist in my opinion two major advisable templates for the tactical level (in addition to calling for striking from a distance only); elusive raids and elusive ambushes. "Elusive" means in this combat mostly that neither raiders nor ambushers allow themselves to become fixed*; they attempt to disrupt spotting, identification, communication to enhance their survivability - and on top of that they vanish in time, making the "in time" challenge for the attacker even more challenging. This in turn means they need to finish their action real quick.
Even though "raid" / "ambush" sound offensive / defensive, the offence (attack) / defence categories have probably ceased to be relevant. A more relevant categorization is certainly whether a certain area is controlled by one side or disputed. This is especially relevant as a description of the safety of (road) marches through the area. A unit with an area skirmish mission may stage ambushes and raids depending on circumstances. Operational offence in this context means that the area of operation is being extended into a formerly enemy-dominated area. Operational defence would mean that the enemy is doing this. Aside from this, only the passing through of a formation through the skirmish area could be considered an offensive move, but it could in fact be a withdrawal through an infested area!
The interesting thing about this is that in my opinion small unit- and unit-level defence has merged with offence. The difference was already often theoretical for a while (just remember the successive counter-attacks of WW1 which made it almost impossible to tell whose army was on the offence and whose was defending after the first few days of an offensive).
More about this later.
S Ortmann
*: "fixed" in military terminology means that you don't dare / cannot move because of the enemy's effort. It's only a subset of "static", not entirely the same.
P.S.:
I don't care much about the division in waves. What counts to me is what has been done so far, what's the influences today and what's left to do now.
I'm 100% sure that almost nobody will grasp this stuff because (a) I don't express it well in such a short form and (b) it's 'different'. I can't help it, am too busy for writing a book these days.
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