The role of submarines in Warfare

The strategic level of war concerns the overall conduct of the war, the approximate forces that will be made available, and the weights and efforts required in various theatres. The operational level of war is the one below and is primarily concerned with how to achieve the strategic aims of the conflict with the forces allocated. It involves the planning and conduct of campaigns and key operations in order to achieve the strategic aim. It provides the link between the strategic and tactical levels of command.

22nd Dec 2010

The strategic level of war concerns the overall conduct of the war, the approximate forces that will be made available, and the weights and efforts required in various theatres. The operational level of war is the one below and is primarily concerned with how to achieve the strategic aims of the conflict with the forces allocated. It involves the planning and conduct of campaigns and key operations in order to achieve the strategic aim. It provides the link between the strategic and tactical levels of command. The tactical level of warfare is the basic level. This is where opposing forces actually meet, where objectives are unambiguous; like finding and sinking an enemy ship. It relates to both the planning and execution of battles and engagements and fundamentally relates to combat with the enemy.

Whilst submarines may be considered a strategic asset in the context of a total force, they do not normally represent a strategic capability - except in the case where they are charged with carrying and hiding nuclear ballistic missiles and, when called upon to do so, having the potential to inflict severe damage on whole societies.  However, submarines are significant operational assets. They can contribute significantly in all three areas of maritime operational warfare; sea control, sea denial and maritime power projection. They are a vital element in any serious naval power’s order of battle and, noting the fact that surface forces opposing a submarine threat need to build up a defensive frame that is complicated, expensive and vulnerable, they are increasingly being acquired by medium and small navies.

This article seeks to explore the characteristics of a submarine that make it a potent operational tool and then discusses how they contribute to sea control, sea denial and maritime power protection.

Operational Characteristics
The operational characteristics of submarines are operational stealth, endurance, freedom of movement, flexibility and lethality. When packaged together they provide mission advantage and potency at sea, even against an enemy that is, at least in theory, superior. Each characteristic is now discussed.

Operational Stealth
Operational Stealth is afforded to the submarine because it operates below the sea surface in a medium generally unfavourable to counter-detecting sensors. Once fully submerged, a submarine remains virtually invisible to all but the most capable Anti Submarine Warfare (ASW) forces.

The significance of a submarine’s operational stealth is arguably growing as countries develop regional/global ocean surveillance systems. Systems which build a wide area maritime picture utilising space, airborne, surface, sub-surface and land based sensing systems - coupled with a network centric warfare requirement for above water assets to have near continuous communication - have amplified the value of the submarine’s operational stealth capabilities. Surface and airborne assets have had their ability to hide their location and intentions eroded.

Operational stealth provides the submarine command with three very significant military advantages; covertness, initiative and survivability. (KYM TO TASHA, BPS).
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Covertness bestows the ability to conduct an operation without being detected. The ability to operate covertly is fundamental to the military effectiveness of the submarine. In times of rising political tension, it is a submarine’s covertness that provides a government with a hidden local lethal asset without the penalty of exacerbating or escalating the political scenario.

In 1977, the Argentinean government was pressing the British Government in the hope of gaining control of the Falkland Islands. The British did not want to complicate negotiations by visibly deploying forces, yet they wanted to be prepared in the event that Argentina went ahead and seized the islands. A surface fleet deployment of two frigates and one submarine, DREADNOUGHT, was made and rules of engagement were drawn up, although it was only the submarine that was allowed into the immediate vicinity of the islands: the surface ships remained more than 1000 miles away. Because of the submarine’s covertness, the Royal Navy was able to be deployed to the region without publicity. The Argentineans were never aware of the deployment and after tensions eased, it was quietly withdrawn.

A submarine deployment is an easy decision to reverse if a Government has a change of heart because it can be done without looking like a back-down.
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Initiative is the ability of a submarine to operate with uncertainty of presence for the enemy, both in terms of location and numbers of submarines.

It provides the submarine with the military advantage of surprise, with the submarine Commanding Officer deciding if and when to reveal his actual presence to the enemy. Recent events in Korean waters have reminded us that an explosion underwater is often the first signal a surface ship Commanding Officer has that a submarine is in close proximity.
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Operational survivability is the ability to operate in hostile environments with little or no risk. To avoid most threats, submarines just need to submerge. While surface ships have to be concerned with defence against attack from sub-surface, surface and air launched weapons, submarines rarely do. This relative immunity also allows them to work unassisted. While a surface ship relies on escorts and auxiliaries whenever they put to sea, submarines can operate alone.

Stealth provides protection for the submarine 24 hours a day and contributes greatly to the probability of mission success. It is interesting to consider that during the Falkland’s War the Argentinean submarine SAN LUIS operated in the main areas of the British task force during a 36-day patrol, at some stages firing weapons against the British fleet, and yet its Commanding Officer reported that throughout that period “There was no effective counter attack”. The British fired more than 150 weapons with no hits scored - with the implication that every weapon expended by the British was against a false target. Britain, considered NATO’s ASW specialist at the time and arguably the best in the world, experienced firsthand how difficult prosecuting submarines can be. Obviously, Britain's ineffective ASW operations could have led to major, even prohibitive, setbacks for the task force.

A submarine’s operational survivability must also be considered in the context of emerging weapon systems which may have grave consequences for above water assets. (KYM TO TASHA, BPS). In development are non nuclear electromagnetic pulse and high power microwave weapons that use or direct a form of radiation to degrade or destroy microcircuits, computers, radar and other sensors, communications networks and other electronic systems so important in modern warfare. These weapons are likely to be delivered using short range ballistic missiles. Thermobaric weapons, which destroy by generating heat and pressure, are also under development. Such missile warhead or bomb delivered weapons produce large explosive effects for their small size. Finally, under development are low orbit hypersonic weapons and high-speed projectiles that utilise electromagnetic rather than chemical propellants. These weapons are likely to render modern ship point defence systems ineffective. By and large, a submarine is invulnerable to such weapons.

Operational Endurance
Submarines are also characterised by their operational endurance, i.e. the number of days they can remain at sea unsupported. They have an ability to deploy and remain within an area of operation for a lengthy period of time without the need for re-supply.

US submarines usually carry supplies for 90 days and routinely stay on station, alone and submerged for 60 days or more. They are, however, capable of carrying supplies for up to 120 days. Large conventional submarines like Australia’s Collins Class are reportedly designed around a 70 day patrol. Smaller conventional submarines such as the Pakistani Agosta 90B AIP submarine has an endurance of 60 days whilst German Type 214s and French Scorpenes have advertised endurances of 50+ days. The Commanding Officer of the Argentinean submarine ARA SAN LUIS during the Falklands war stated that he could patrol for 60 days in his 1200 tonne Type 209 before needing to refuel and re-supply.

By contrast, a single frigate has only enough fuel to be away from port for about 12 days. A group of warships supported by a replenishment ship has an endurance of about 30 days.

Freedom of Movement
Freedom of movement is afforded to the submarine by its stealth and endurance. Freedom of movement is the ability to move from place to place with relative impunity and the ability to access into any chosen area within an area of operations, including areas that are not easily accessed or occupied by other friendly assets, to achieve positional advantage.
Submarines generally have unfettered movement within an area of operations which means they can shift position within the area as the operational or tactical situation changes. Whilst dived they are generally unhampered by rough seas and poor weather.

Stealth, endurance and freedom of movement in combination allow a submarine to exert influence over a very wide area even if it can only deliver its weapons over a small expanse of ocean. Since naval forces do not know the location of a patrolling enemy submarine, they must assume that the submarine could be anywhere and plan their operations accordingly. Sun Tzu said “The enemy must not know where I intend to give battle. For if he does not know where I intend to give battle, he must prepare in a great many places … and when he prepares everywhere he will be weak everywhere”.

A submarine's wide range of sensor and communication payloads, its effectors and its ability to operate covertly and independently across the area of operations provides a Force Commander with an ability to task a submarine with a number of different mission types as the strategic, operational or tactical situation changes.

As an example, at the operational level, a submarine might arrive in an area and be tasked first to insert Special Forces, followed by ISR, followed by a mine lay, then be re-tasked to deliver a land strike package and finally be ordered to engage enemy shipping and submarines.

Effectors such as torpedoes, anti-ship missiles and land-attack cruise missiles, give submarines the ability to bring considerable force to bear on the enemy at the tactical level. Heavy-weight torpedoes can deliver a large explosive charge to an enemy submarine or ship, resulting in unit kill. Anti-ship cruise missiles, whilst generally having a lesser effect on a ship than a heavy-weight torpedo, provide the submarine with a valuable stand-off capability. Even if they don’t sink the ship they are still likely to cause sufficient damage to force its withdrawal from the conflict. The destructive capabilities of land attack missiles are well understood, having been used in numerous conflicts since the early 1990’s.

Ironically, in recent times submarine users have shifted away from absolute lethality in their payloads to allow submarines to have greater utility and relevance in lower level conflicts. There are many examples of their expanded utility, albeit with reduction in lethality, the delivery of Special Forces is one example. Although Special Forces can cause a lot of damage to enemy assets and personnel and they can apply force in a controlled manner. A second example is seen in the planned arrival of submarine launched wire guided missiles such as IDAS or AIM 9X, which will soon be deployed from German and US submarines respectively. Designed to shoot down anti-submarine helicopters and aircraft, they also provide the submarine with a capability to employ weapons below the unit kill level. Hoistable mast mounted guns are also on the horizon.

Operational Roles
Command of the sea involves sea control, sea denial and maritime power projection. Submarines, either acting independently with access to the maritime knowledge network or as a tightly integrated component of a task force, are vital contributors to achieving command of the sea.

Sea Control
Sea control is defined as that condition which exists when one has freedom of action to use an area of sea for one’s own purposes for a period of time and, if required, deny its use to an opponent. This includes the air space above the water mass, and the seabed below as well as the electro-magnetic spectrum. Control of the sea can be limited in place and in time and the required extent is determined by the task to be done. It includes control over own bases, over forces in transit, over focal points and over an area of operation. It allows a navy to protect sea lanes of communications, deny the enemy commercial and military use of the sea, established areas for the projection of power ashore and protect naval logistic support to forward deployed battle forces.

Control of the sea can be accomplished through decisive operations by destroying or neutralizing enemy ships, submarines, aircraft, or mines; by disabling or disrupting enemy command and control by destroying or neutralizing the land-based infrastructure that supports the enemy’s forces relevant to control of the sea; by seizing islands, choke points, peninsulas, and coastal bases along the littorals; or by conducting barrier operations in choke points that prevent enemy mobility under, on, and above the sea.
Submarines can be relevant to a number of sea control activities.

Well before and indeed immediately prior to conflict submarines can enter an area and conduct a range of intelligence, surveillance and reconnaissance (ISR) activities. In doing so, they can gain an understanding of the geospatial attributes of operational area, the patterns/doctrine/tactics and the capabilities of the enemy. Submarines can also continue ISR operations up to and beyond the point where hostilities have ceased. If conducted carefully, these ISR operations can be carried out without diplomatic or military provocation.

At the commencement of hostilities the submarine can conduct land strike operations, with the aim of taking out command and control assets and other enemy sea and air control capabilities. After hostilities start the submarine can continue land strike, carry out mine countermeasure operations or carry out traditional submarine anti-shipping and anti-submarine operations. They can do so in an interdiction capacity, attacking enemy offensive naval and logistic support shipping, or in a strike capacity, attacking shipping deep in enemy territory.
A submarine’s ability to attack at a time of its choosing can have a dramatic effect on a belligerent. Whilst an enemy can choose to seize control back from a force supported or dominated by submarines, this is only a serious option if they possess a sophisticated, well practiced ASW capability. The decision to pursue the submarine threat will tie up a significant number of assets that could otherwise be used in other campaign activities.

During the Falkland’s War the British allocated one carrier, eleven destroyers, five nuclear powered submarines, one diesel submarine and over 25 helicopters to the ASW task. These assets all but depleted their available stores of sonobuoys and expended so many weapons that the United States was called upon to provide replenishment for British inventory. All of these assets and resources were used to counter one small diesel electric submarine, SAN LUIS.

As recently as 2004, the two day prosecution of an old and noisy Chinese HAN class nuclear submarine in Japanese waters required an entire United States Navy P-3 maritime patrol aircraft squadron, numerous Japanese Defence Force P-3s, a number of United States Navy submarines and surface ships and a T-AGOS surveillance ship equipped with towed sonar.
It is also true to say that suspecting there is one submarine in an area and reacting to it does not mean that the enemy is safe in other areas.

The nature of submarines also fosters the use of deception to effect sea control. During the Falklands War the Argentinean submarine SANTIAGO DEL ESTERO was inoperable during the conflict due to an inability to submerge, but Argentina - convinced that the United Kingdom was in receipt of satellite intelligence - went so far as to reposition her to a covered location in the hope that the British would conclude she was on patrol.

Sea Denial
Sea denial is the military term describing attempts to deny the use of the sea by enemy forces, or by merchant traffic engaged in war sustaining trade, in situations where one’s own forces are unable to establish sea and air control. Sea denial is in many ways an inverse form of sea control.

The mere fact that a submarine is active, or is even suspected of being active, in a particular region can deny the enemy the use of that area. Overt signalling or subtle hinting of a submarine’s presence to an enemy can serve to deny that enemy the ability to utilise areas. Provided the capability exists, there may be no requirement to actually deploy a submarine to achieve sea denial.

The Argentinean retreat after the sinking of the old cruiser the GENERAL BELGRANO provided the Royal Navy with far greater freedom of movement in the region than might have otherwise been possible.

A further example of the strike threat posed by a submarine came during Operation El Dorado Canyon, an air strike operation against Colonel Qaddafi’s Libyan regime in April 1986. The presence of United States Navy nuclear attack submarines was an important reason for Libya’s six Soviet built diesel submarines remaining in port during the pre-strike and post-strike positioning of the United States Navy's Sixth Fleet units.

Both Argentina and Libya altered their national strategies because modern submarines were present in the area of operations. These cases are both demonstrations of submarines effecting sea control.

Maritime Power Projection
Sea control, once achieved, establishes the environment for more direct efforts in relation to the land. Maritime forces can shape, influence and control this environment, as well as deliver combat forces ashore if necessary. The delivery of force from the sea is defined as maritime power projection. It can involve seaborne dispatch, transportation and insertion of land forces or the bombardment of land targets by guided or unguided weapons from seaborne platforms.

Submarines can contribute directly to Maritime Power Projection through the embarkation, transport and insertion of Special Forces and through a land strike capability. They can also assist indirectly through activities such as covert surveys or rapid environmental assessment and by offering protection to amphibious task groups.

The operational characteristics of submarines are operational stealth, endurance, freedom of movement, flexibility and lethality. When packaged together they provide mission advantage and potency at sea, even against an enemy that is, at least in theory, superior.

Submarines offer their owners both close and distant defence against direct assault, the ability to disperse and deter countering forces, power projection and intelligence gathering without significant risk of provocation and the ability to conduct a wide range of tactically effective operations once hostilities commence. They can be used to effect sea control and sea denial and to contribute to maritime power projection operations.

The next article in the series is – Submarine Roles and Functions

APDR at a glance