Commonwealth Army Doctrine
The Commonwealth Army's main operational doctrine is known as "Integrated Mobile Operations". Developed in the 50s and 60s, it drew together lessons learnt from the mechanised battles of the Great Fascist War and the advent of tactical nuclear weapons. It hypothesised that, in an environment characterised by the massed usage of weapons of massed destruction (or, in the contemporary environment, precision-guided munitions), large concentrations of forces which stay together for excessively long periods of time are liable to be quickly detected and consequently suffer the murderous effects of deadly new weapons. As such, dispersion, concealment and mobility are the most important contributors towards survivabilty, with concentration only achieved just before a major engagement and rapidly reversed immediately afterwards. In an environment with low force density and in the absence of fixed front lines, war will be characterised by duels between mobile combined arms groups which can maneouvre at will, placing a premium on aggressive leadership and initiative from the lowest levels of command. Overall, the current Arthuristan ground forces organisation and doctrine are completely optimised for high intensity operations against peer great powers, making no compromises for asymmetrical warfare.
Integrated Mobile Operations
At the operational level, Arthuristan ground forces are focused on fighting the "Air-Land Battle in network-centric conditions". The general shift of modern militaries from large scale mechanised warfare to 'small wars' and counter-insurgency is conspicuously ignored by Arthuristan planners. Rather, the Commonwealth Army has remained largely focused on combating "peer threats" - well-organised and equipped forces from hostile great powers.
Arthurista's land warfare doctrine, known as Integrated Mobile Operations, is thoroughly focused on maneouvre warfare. In defence, it envisages the use of mobile, combined arms battlegroups to slow, attrit and contain and enemy attack. In offence, armour and artillery are rapidly concentrated to take advantage of fleeting opportunities and break through vulnerable spots. In both, tactical air power, theatre ballistic missiles and vertical envelopment forces (company to brigade-sized air assault and parachute units) are used predominantly to interdict and disrupt the enemy's operational rear in order to curtail his ability to fight a maneouvre battle, especially his ability to shift reserves to concentrate combat power in time and space for a decisive encounter.
Commanders at all levels are urged to keep his forces moving with a view to engage and destroy the enemy force, or else avoid being pinned down by an enemy attack, rather than statically defend pieces of terrain, or launch frontal assaults against enemy held features, unless there is absolutely no other option available. At all times, Arthuristan forces must control the tempo of operations and retain the initiative, by maximising his capacity to maneouvre at any given time and minimising his enemy's ability to do the same. To this end, continuous reconnaissance must be mounted with ground, air and unmanned assets in order to keep the enemy under constant surveillance, while at the same time ceaselessly attempt to hunt and destroy the enemy's reconnaissance assets in order to gain information superiority over the battlefield. Likewise, enemy C4I capability must be rapidly degraded or eliminated through a vigorous prosecution of the electronic battle, as well as by locating and destroying the enemy's headquarter units and communication nodes. Forces must operate as dispersed swarms, rapidly concentrating in order to achieve an operational objective, then disperse as rapidly as possible before they could be caught by heavy conventional, PGM or WMD attacks.
In summary, the modern air-land battle was described as akin to naval tactics - combined arms groups rove at will over the landscape like squadrons of ships in the sea, concentrating when they see an opportunity, duelling with opposing combined arms groups at decisive junctures, then rapidly dispersing before being caught by the deadly effects of precision fires or by a massed counterattack, all the while maintaining informational superiority over the enemy such that ones own artillery, tactical air power, ballistic missiles and other deep fires elements can continuously strike at the enemy's key assets while preventing the opposing commander from doing the same. Knowing when to disperse one's battlegroups and when to concentrate them is considered the acme of skill for brigade and divisional commanders.
In terms of force structure, the Commonwealth Army attempts to achieve the best balance between tactical flexibility and the ability to mass combat power at the decisive point. A great deal of focus is placed on the operational level of warfare and the art of concentrating armour, tactical air assets and, above all, artillery, in order to deliver a decisive blow, while dispersing these assets in time and space before and afterwards in order to avoid a similar blow from the enemy. Much emphasis is placed on commander initiative on all levels, from the smallest fireteam upwards. An illustrating fact is that while many junior officers serve on short commissions, nearly all senior NCOs and Warrant Officers are career-long professionals.
It is envisaged that such a force is flexible enough to operate and survive in very hostile environments, even where precision-guided or CBRN weapons are used intensively by the belligerent parties, and still retain enough potential to concentrate combat power at the opportune moment and impose a decisive result.
Defensive operations
Arthuristan defensive doctrine is shaped by the fact that, in defence, the aggressor typically possesses the initiative at the outset. Preparing static defenses is therefore almost futile - the focus of the Commonwealth Army must be on mobility and rapid force concentration to deal with threats as they arise.
In a typical corps-level defensive operation, the corp's divisions will be split into battalion-sized battlegroups, each a combined arms unit of maneouvre elements and self-propelled guns. Operating in swarms, they will be tasked with forming a screen, slowing and attriting the enemy offensive force with delaying actions and local counterattacks, limiting his rate of advance, causing maximum damage in conjunction with the corps' artillery reserve, half of which would generally be assigned to support the defensive phase of the operation, as well as masking the concentration of the mobile heavy reserve. Meanwhile, ballistic missiles and tactical air assets will be employed to interdict his supply routes, as well as strike at enemy formation HQs, communications hubs, fuel and ammunition dumps and other vital targets.
In the defensive phase, these autonomous formations will hit and run in a decentralised manner, rapidly grouping with other similar battlegroups for an engagement, then scattering before they could be caught by a major deliberate assault, adhering to the classic maxim: "march dispersed and fight concentrated", a principle especially important if chemical or tactical nuclear weapons are liberally employed. The emphasis will be on conducting a thoroughly mobile campaign - the static defence of fixed features is to be avoided if possible, except where the terrain is overwhelmingly favourable to the defender and sufficient numbers of battlegroups could be concentrated to defend it. The catchphrase drilled into every officer cadet in training is "fight over the ground, never for the ground".
Once the enemy's main line of thrust has been identified, and the battlefield 'shaped' satisfactorily, the corps' main reserve formations, typically multiple heavy combined arms brigades supported by the other half of the corps artillery reserve, will be used as a unitary body to counterattack at a key point, aiming to cut off the greater part of the enemy spearhead, break behind the Forward Edge of the Battle Area (FEBA) and into his operational rear, with the aim of converting the localised breakthrough into a strategic counteroffensive, collapsing the enemy's main force altogether.
As a rule of thumb, the transition from operational defence to strategic counterattack ought to be done as rapidly as possible in order to minimise the time available to the enemy to fortify any ground gained, provided that it is adequately planned and prepared.
Offensive operations
Offensive operations are preceded by the infiltration of special reconnaissance behind enemy lines. There, in conjunction with aerial and electronic reconnaissance assets, they will attempt to map the enemy's disposition in the FEBA and rear areas, creating the basis for an offensive plan.
Offensive operations are relatively straightforward affairs. A battlegroup, brigade, division or corps will advance in a roughly diamond-shaped formation - with a reinforced reconnaissance element acts as a forward detachment or screen, mech-heavy holding formations guard the flanks and attempt to find a weakness in the enemy front, while a tank-heavy unit acts as an operational maneouvre group exploit the breach and collapse the enemy's rear areas.
In the tactical sphere, the behaviour of Arthuristan units on the attack is identical to that when defending - operate in swarms of small mobile groups, avoid 'turtling' static-defence units (though keeping them under surveillance), disperse and evade in the face of concentrated fires and counterattacking troops, call down precision-guided indirect fire to 'pin down' mobile enemy concentrations, then rapidly concentrate and destroy hostile combat formations by attacking them in the flank or rear. Small, combined arms battalion groups constantly on the move can avoid detection ad being targeted by deadly concentrations of precision-guided munitions, while increasing the chance that they will encounter enemy rear area assets and take them by surprise. Where the decisive engagement is about to be fought, multiple battlegroups can rapidly concentrate to win the subsequent action, then dispersing again before they could be caught by a concentrated counterattack or heavy enemy precision fires. As in defensive operations, the ability to grasp when to disperse and when to concentrate ones battlegroups is considered the acme of skill for brigade and division commanders.
Artillery and air assets will play distinct roles. The task of artillery is to provide close support during the breakthrough operation. To this end, the division or corps commander will concentrate the entirety of his artillery reserves (usually two MLRS regiments for the former and a heavy artillery brigade for the latter) to support the main axis of advance. Gun artillery operating in support of the main axis will usually be allocated 50% more PGMs and DPICMs than regiments in holding sectors. Tactical air assets and theatre ballistic missiles, on the other hand, will be given the role of deep strike - to interdict the enemy's main lines of supply, reinforcement and retreat, isolating the FEBA and thereby facilitating in the collapse of the enemy's resistance.
Reconnaissance
There are two types of reconnaissance ("recce") units in the Commonwealth Army - Formation Reconnaissance and Special Reconnaissance.
Special Reconnaissance units are highly trained small, stealthy teams of light infantry or special forces which operate beyond the coverage of a division or corps' artillery umbrella, penetrating far beyond the Forward Edge of the Battle Area ("FEBA") on foot or in light vehicles to bring back high priority intelligence for higher headquarters.
Formation Reconnaissance is predominantly the responsibility of armoured cavalry units, supported by tank destroyers and main battle tanks. Their task is to operate at the edge of the FEBA and provide actional intelligence to its parent formation. Unlike reconnaissance units in many contemporary armies, with an emphasis on the information gathering role at the expense of other missions, Arthuristan armoured cavalry leverages its organic fighting power, supported by indirect fires, helicopter and air support, to operate aggressively against the opposing force. In both offensive and defensive operations, armoured cavalry units will embark on a coordinated hunt with other friendly manned and unmanned assets for enemy reconnaissance elements, in an attempt to 'blind' the opposing force and impose informational superiority. In an offensive operation, nimble squadrons and regiments of armoured cavalry may also penetrate behind enemy lines to seek and destroy high value 'soft targets' such as divisional supply columns or command posts in conjunction with artillery, tac-air and ballistic missiles. In extremis, they may even be tasked with capturing and holding vital pieces of terrain behind enemy lines before the arrival of friendly units, such as bridges rigged for demolition by the opposing force. Naturally, they are also capable of performing the usual reconnaissance tasks of avoiding contact and conducting surveillance on the enemy.
Decapitation
Arthuristan doctrine places significant emphasis on 'decapitation' - to remove the enemy's ability to exercise effective command and control by constantly attempting to identify, locate and, once having done so, neutralise the enemy's tactical and operational headquarters. Significant resources are invested in electronic support measures to enable this.
Once identified, a field headquarters may be neutralised using 'hard kill' and 'soft kill' measures. The former is to physically eliminate it, or at least suppress or disrupt its operations to a sufficient degree that it is rendered ineffective. A proportion of Arthuristan remote-fires and tactical air assets are constantly on standby and held in reserve for this role. Soft kill generally involves the use of electronic warfare. 'Silent' jamming is generally preferred in order to prolong the period of time before the opposing headquarters realises that it is incommunicado.