Exposed on the High Seas

The 'Achilles' Heel' of every aircraft carrier is its inherent vulnerability. It weighs 100,000 tons, carries 60 to 80 aircraft and is difficult to conceal or defend. So, how do you protect it against hostile attacks on the maritime battlefield?

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Since the 1930s, aircraft carriers have constituted the backbone of US naval power and used to exhibit American strength worldwide. The US Navy currently maintains 11 aircraft carriers and another one will join it by 2020. This is a 1:3 ratio and the objective is to maintain four carriers in continuous operation, two assigned to US Pacific Command (USPACOM) and two assigned to US Atlantic Command (USACOM).

The operational doctrine for the carriers was based on a number of primary elements: a logistic base and airbase at sea, a forward intelligence force charged with spotting enemy naval forces, a forward prompt response strike force whose operation resembles that of cavalry on the ground, a major naval vessel capable of defeating any other vessel in the maritime theater, a deterring nuclear strike force and a tool for the accomplishment of geo-political objectives.

The Maritime Theater is Wide Open

Every aircraft carrier has one primary 'Achilles' Heel' – its inherent vulnerability. An aircraft carrier weighs 100,000 tons, carries 60 to 80 aircraft and is difficult to conceal or defend. The assumption that formed the foundation for the operational doctrine of aircraft carriers was that the maritime battlefield enables carriers to operate with a relative degree of secrecy. The defensive concept for aircraft carriers relied primarily on a naval aerial force capable of destroying any threat within a radius of about 75 miles around the carrier.

But the maritime battlefield has changed. Satellites, UAVs, mission aircraft, long-range Radar systems and optical surveillance measures were acquired by many countries, and the aircraft carrier lost its relative secrecy. The enemy knows where it is at any given moment, and if its location is known – it is vulnerable.

Another factor that entered the battlefield and threatens the aircraft carriers is the category of long-range precision guided munitions (missiles and rockets) that relies on the various positioning satellites. If the aircraft carrier can be identified and spotted, a precision-guided missile or rockets may be launched against it. The Chinese, for example, developed DF-21D and DF-26, dedicated ballistic missiles designed to engage aircraft carriers. Additionally, some cruise missiles were adapted specifically to the maritime environment, like the Russian made Yakhont (P-800 Oniks) missile, and current precision rocket systems can hit naval targets at ranges of hundreds of kilometers from the shore.

Along with surveillance measures and long-range missiles, the aircraft carrier also faces the obstacle of maneuverability. An aircraft carrier is a huge naval vessel, and environments that contain natural or man-made obstacles are not readily accessible to aircraft carriers. In the South China Sea, for example, one of the objectives of the man-made islands built by the Chinese is to prevent US aircraft carriers from entering the area.

A Threatening Coastal Environment

One of the functions of the aircraft carrier is to support attacks against coastal targets, either directly by vessels belonging to the same task force using cruise missiles and guns and by the fighter aircraft it carries, or by providing logistic support (fuel, ammunition, food and maintenance) to forward offensive elements. In order to engage coastal targets, the aircraft carrier should approach to within the striking range of the aircraft it carries. As the effective range of the shore-based interception resources (rockets/missiles) has increased, the aircraft carrier faces a serious problem. For this purpose, such resources as the railgun are currently under development, to enable the aircraft carrier to accomplish the mission from a longer range.

The effectiveness of the employment of aircraft has also decreased owing to the deployment on the shore of long-range, high-precision surveillance Radar systems, along with long-range air-defense systems. The implication is that the effectiveness of employing the fighter aircraft carried by the aircraft carrier for attacking targets on the shore has decreased as well.

The limitations outlined above with regard to intelligence, missiles and maneuverability have significantly reduced the areas aircraft carriers can access and operate in. Under these circumstances, the advantage of the aircraft carrier has diminished. One of the ways to retain that advantage is to change the operational doctrine of the naval force.

In a scenario involving a wide-open maritime theater, the primary function of the aircraft carrier is that of a floating logistic base. In order to defend this floating logistic base, naval vessels with anti-missile capabilities should be grouped around the aircraft carrier, as they can significantly improve its survivability.

In order to cope with the enemy's long-range surveillance Radars, some of the aircraft carried on board the carrier should be replaced by stealth aircraft. These aircraft will form the breakthrough element charged with the task of destroying the coastal Radars and establishing a threat-free corridor leading to the shore. Another element for coping with the enemy's surveillance resources is providing the aircraft carrier with a long-range offensive missile capability. This may be accomplished by using railgun and cruise missile systems – both of which are currently under development in the USA.

Another aspect of the new doctrine should involve a change in the strike force make-up. Instead of relying primarily on aircraft and cruise missiles, whose effectiveness is limited in a wide-open battlefield where the enemy employs defensive systems, and are also extremely costly, other fast, covert solutions may be considered. Among other things, the USA currently develops LCS type fast and stealthy missile frigates, manned and unmanned missile-carrying submarines, submarines for special operations units (for shore operations) and aerial and naval unmanned vehicles, including swarms.

In this way, the aircraft carrier may be used as a forward logistic base and as a factor in the attainment of air and naval superiority within a limited radius, with the attacks against the coastal targets performed by fast, covert elements. Admittedly, the battlefield will remain wide open owing to satellites that are difficult to deal with, but preliminary handling of the enemy's land-based and airborne surveillance resources will minimize the exposure of the attacking force and enable it to retain the advantage even in a wide-open maritime theater.

The US naval forces also aspire to achieve superiority in the underwater medium. They are attempting to accomplish it by means of a network of submerged sensors that would identify enemy submarines and by employing unmanned vessels for spotting submarines and mines that would operate around the clock as a 'comb' in 'hot' maritime theaters.

With regard to unmanned vessels, in the USA they reached the conclusion that quantity is preferable to quality, so they are currently opting for swarms. The objective is to assemble a swarm of USVs, UUVs, UAVs and UGVs that would be thrown into the battlefield in large numbers and operate autonomously. This tactic will lead to an immediate overload on all of the enemy's surveillance and defense systems and make it possible to destroy them more easily, at a relatively low cost and without the loss of human lives. This is one of the reasons owing to which the US authorities want to develop unmanned aircraft carriers.

Even if the USA decides to revise their doctrine and develop all of these technologies, over time the advantage of the aircraft carrier will be eroded in wide-open maritime theaters. In a confrontation opposite a technologically-advanced military, the aircraft carrier will constitute a high-priority, high-value target and it is safe to assume that it would be neutralized during the first few days of the fighting.

Along with technologically-advanced countries, low-cost, highly effective solutions to ranges of dozens of kilometers, capable of closing the gap, may be found even in coastal environments where no cutting-edge resources are available for spotting and intercepting naval vessels at long distances. Antitank guided missiles for ranges of 30 km, fast self-exploding boats ("kamikaze boats"), fast manned/unmanned vessels carrying antitank missiles and used to extend the interception range (the vessel's range plus the range of the antitank missile) and low-cost rockets to short ranges, launched from the shore or from the fast vessels – all of these resources threaten the aircraft carrier within ranges that are shorter than those of the precision-guided missiles, but the offensive measures in question are almost impossible to intercept.

From a strategic point of view, the limitations currently imposed on the employment of aircraft carriers for the purpose of exhibiting strength compel the USA to build land bases as an alternative. This trend may be observed in Asia, where the USA established bases in the Philippines and used the bases of Singapore, and in all probability will use those of India as well in the near future. These bases were added to the list of US bases that already exist in Japan and South Korea. In this way, the USA evades the limitations China imposes on aircraft carriers by means of the man-made islands built in the South China Sea.

Small Navies

The insights gained from the discussion of aircraft carriers also apply to smaller navies that operate helicopter carriers and missile frigates. On the modern battlefield, the assumption is that the navy operates in a state of complete exposure. For this purpose, missile frigates are fitted with missile defense systems. One example is the Barak-8 system fitted on board the missile frigates of Israel and India.

Admittedly, these systems protect the vessel they are mounted on or a group of vessels, but they consume massive energy resources from the vessel and also occupy the functional and storage spaces that could have been allocated to offensive systems. The implication is that a missile frigate whose function is to attack coastal targets, allocates a substantial part of its resources to the task of protecting itself, so its effectiveness as an offensive vessel is impaired. Moreover, these systems are dependent on the amount of interceptors available, so in a coastal environment where surface-to-surface cruise missiles abound, the timeframe available to the missile frigate in order to attack coastal targets is very short and in some cases nonexistent.

The implication is that even small navies that do not have aircraft carriers encounter wide-open maritime theaters with expansive areas out of which offensive operations cannot be staged, and in fact – where they can hardly operate effectively. In order to bridge this gap, offensive measures that evade the shore-based threats and the missile-based threats should be considered.

Another measure is the cruise missile. If a surface-to-surface missile or a precision-guided rocket is effective to a range of 300 km, an offensive cruise missile to a range of more than 300 km fitted to a missile frigate will enable attacks against coastal targets from outside the danger zone. The problem with this solution is the fact that it is expensive and not economical. If the attack is based on the launching of missiles from such ranges, then in confrontations close to the border, why not fire them from a ground-based battery located inside the sovereign territory of the state with almost no risk, or out of a submarine? Long-range cruise missiles are undoubtedly an effective solution for wide-open maritime theaters, but they are costly and can be intercepted. Consequently, in all probability they will only be employed to engage a handful of high-value targets.

Another resource is the employment of unmanned vehicles. Such platforms now operate on the surface, under the surface, in the air, on land and in outer space, and can operate in a vector-oriented manner, autonomously, or as a swarm – to maximize the entire range of capabilities of the various media. The advantages of the employment of unmanned vehicles pertain mainly to the economic and political aspects.

With regard to the economic aspect, the cost of such mass-produced platforms is lower than that of cruise missiles or precision-guided munitions, mainly with regard to vehicles originally intended to be disposable.

With regard to the political aspect, the employment of unmanned vehicles does not involve troopers killed, wounded or taken prisoner. Consequently, as far as the decision makers are concerned, the employment of unmanned vehicles can provide an advantage in offensive operations.

Looking at the over-all economic equation, offensive action is cheaper than defensive action. Employing swarms of such vehicles in the maritime theater against naval and coastal targets, autonomously or semi-automatically under centralized control from a naval vessel located far away from the shore can offer a solution that evades the risks on the shore.

Yet another option involves the utilization of the underwater medium. Along with unmanned vehicles, small manned vehicles like the dry submarines being developed by Lockheed Martin for the US Special Forces can help retain the element of surprise in an operation involving a dismounted attack against a coastal target. A special operations unit arriving on the shore unexpectedly and dealing with the coastal defenses and surveillance resources can clear the maritime theater and enable the missile frigates to approach closer to the shore.

Another school of thought calls for the development of dual-purpose naval vessels, namely – vessels capable of operating both on and under the surface as required. In this way, the element of surprise may be retained in offensive operations and the underwater medium may be utilized for defensive purposes. For example, a vessel of this type may approach the shore under the surface, land UGVs to deal with the coastal defenses, return under the surface, then surface at a safe distance and launch missiles at the coastal targets.

Command of the Sea despite the Limitations

Without a doubt, the fact that the maritime theater is becoming dangerously exposed for offensive naval vessels calls for a new way of thinking regarding the functions of the naval force and the technologies it requires in order to accomplish its objectives. For the purposes of this discussion, it makes no difference whether the naval force in question is the navy of a superpower whose fleet includes aircraft carriers or a medium-size navy whose fleet only includes missile frigates and helicopter carriers. The exposure restricts the offensive capabilities with regard to coastal targets as well as with regard to targets at sea.

The limitations imposed on the use of naval power against coastal targets also raise the cost of the offensive resources that should possess long-range operation capabilities and be accurate and effective but still offer only a partial success ratio owing to the interception resources of the enemy. If the cost of the attack exceeds the operational benefit that may be gained from the elimination of the specific target, then the attack will not be logical. Under such circumstances, the state will not be able to support a prolonged war effort economically.

Along with the economics of war, the limitations imposed on the use of force are also reflected in the risk to human lives and to the naval vessels as a result of the improvements in the coastal defenses. If the political cost of the operation (casualties) and the operational cost (the loss of naval vessels) are too steep, then the attack will not be logical in this case, too.

In view of the above, it would appear that the maritime theater is about to undergo a change similar to the one that the aerial theater underwent pursuant to the introduction of surveillance technologies that exposed the skies. In the maritime theater, too, it appears that the preferred solution involves the employment of unmanned vehicles. These vehicles can operate within an expedient equation – politically, economically and operationally – to achieve superiority even in a wide-open maritime theater.


Maj. (res.) Yotam Gutman is a former IDF Navy officer specializing in C2 and USV systems

Ami Rojkes Dombe is the Tech Editor of Israel Defense


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