This time it is not driven by the threat to transatlantic sea lanes of communication from large numbers of Soviet submarines, but by recognition of the ability of much smaller states to deny access to their littorals with a few submarines (Kilo, left) or mines.
Defense is a poor primary naval mission in general, and a terrible one for submarines. The original Maritime Strategy, conceived and developed in the late 1970s and early 1980s by Chiefs of Naval Operations Thomas B. Hayward and James D. Watkins, made the Soviets play defense because of our demonstrated early offensive ability. What made the Maritime Strategy even more effective was that as Soviet naval forces were pulled back into home (littoral) waters, a very target-rich environment was created. As the U.S. Navy looks to future conflicts in littoral waters, it can draw valuable lessons from this Cold War experience.
ASW Then and Now
To draw analogies between the offensive-minded antisubmarine warfare (ASW) strategy represented by the Maritime Strategy and the need to combat the technology and techniques of a littoral submarine threat in the future, several differences must be considered.
Then, in the principal area of conflict, the Barents Sea, there were many targets, it was fairly noisy, both opponents were very skilled and experienced, and the objective on both sides was attrition-the destruction of each other's naval assets. The principal target, Soviet nuclear ballistic-missile submarines, was a Clausewitzean center of gravity. Both sides employed technique-based skills, which required much practice to perfect. The fight was an extremely fast-paced affair once hostilities commenced-some war games showed loss of 80-90% Soviet and 20-30% U.S. engaged submarines in as few as three or four days.
Now, there are few targets, areas of conflict are very quiet, the infliction of severe damage to U.S. naval units is as good an outcome or better than outright destruction because of desired media exposure, and the loss-tolerance scenario has changed: they are willing and we are not. Significant opposition advantages accrue simply by imposing significant delays to U.S. surface Navy entry into denied littoral waters. Opposition centers of gravity are ashore. The detection, localization, and engagement process is likely to be time-consuming. A dearth of submarine experience by opponents, including at command levels ashore, implies that they will employ tactical concepts that emphasize procedurally oriented skills, which tend to be mastered more quickly than technique-based skills.
This partial list of men-now considerations changes the ASW calculus for the future in several ways, many of which have emerged as insights in Title 10 war games conducted at the war colleges. For example:
* Coalition forces typically are operating under severe timeline considerations—a bad situation is getting worse rapidly, and naval forces must get in quickly to enable entry of U.S. Air Force tactical aircraft, ground forces, and massive supporting sea- and air-delivered logistics.
* Nothing so traumatizes U.S. surface naval commanders as having even a few submarines out of home port and unlocated. In this sense, enemy submarines play a significant role just by remaining undetected.
* The reality of area search by a few platforms against a few very quiet targets in shallow waters is such that weeks might pass before a statistically significant probability of detection accrues. If these searching platforms include nuclear submarines loaded with submarine land-attack cruise missiles or special operating forces, or capable of mine detection and localization, there is a significant opportunity cost to employ these nuclear subs in a search role on the fringes of the theater rather than more aggressively deeper into otherwise denied enemy waters.
* In an attrition-based conflict, ships are more readily sunk by letting water in the bottom (torpedo) than letting the air out of the top (antiship cruise missile [ASCM]). Firing an ASCM is a procedural versus technique-based skill and therefore easier to acquire than shooting torpedoes.1 The heavily damaged ship, with many casualties, also better serves an opponent's desire for adverse media exposure as it is towed home instead of being sunk.2
* The current bane of U.S. ASW planners—the nonnuclear air-independent propulsion (AIP) submarine—is tactically significant if it employs its limited amount of stored energy to maintain a covert stance for as much as a month at 2-3 knots. When it runs at higher speeds, to conduct a torpedo approach, for example, energy consumption increases dramatically. Propulsion energy requirements at 8 knots are 64 times greater than at 2 knots; energy that would have lasted many weeks can be consumed in less than a day.
None of the above is meant to detract from the fact that a U.S. nuclear submarine remains the premiere ASW platform. It rather is intended to highlight that when multi-mission platforms are limited, some difficult choices must be made about their optimum employment. Fortunately, the much larger magazines coming with the nuclear guided-missile subs and future nuclear subs will mitigate significantly these difficult decisions.
Asymmetric ASW Technologies
The above wargaming lessons have implications for the conduct of ASW in the littorals, as in this example. A thinking Third World opponent has a need to deny or significantly slow a U.S. naval incursion into his littoral waters. In support of this, in addition to a mixed bag of sea mines, he will obtain a relatively small number of the very best nonnuclear AIP submarines he can buy. He will outfit these submarines with the very best low-observable, hypersonic, medium- to long-range sea-skimming ASCMs available. The operational concept of employment for these submarines would be to get out of home port early and remain undetected—likely at or near the bottom in coastal bays or inlets behind sensor/mine barriers and "under" cover from hidden surface-to-air missiles and shore-based ASCMs-with constant passive (listening) connectivity to command authorities ashore, perhaps even by presited fiber optic links or short-range acoustic communication nodes. Operating analogous to submerged theater ballistic missile transporter/erector/launchers (TBM/TELs), these AIP units would be prepared to launch ASCMs immediately down a given bearing on order, then quietly reposition to an alternate hide site. This ASCM/AIP submarine concept is disturbingly reminiscent of the TBM/TEL operations against which U.S. forces have been so unsuccessful: it eliminates the need for a manned, reusable asset (airplane or submarine) to risk closing a target to deliver a short-range weapon (bomb or torpedo).
The above concept of operations would call for unique counters by U.S. or coalition forces. Because there are few targets and sensors, the only factor capable of manipulation by U.S. or coalition forces to reduce total search time is to increase dramatically the number of sensors. "Old Think" would conclude that the area(s) in question should be flooded with maritime patrol aircraft, sonobuoys, and submarines. As this is likely to be impractical, unaffordable, or even unsafe for the aircraft, options that better leverage now-available technologies should be considered. These could include drifting sonobuoy-like devices that remain radio-frequency—quiet until detection occurs and/or many small, autonomous underwater vehicles (AUVs) that search a predetermined area and report. Following detection and target validation through embedded rules of engagement and associated logic similar to that employed in sophisticated sea mines, these devices would report to the target grid by satellite uplink that "number 35 has one here at (GPS) latitude xx.xx and longitude yyy.yy." In a scenario where sea or air access by observable search platforms is denied or seriously challenged, these devices might best be injected by larger submarine-launched shuttle AUVs or even by a B-2 Spirit stealth bomber.
Because the detection range of the devices is only a few hundred yards, they are valid aim points for homing weapons. The now familiar sensor-to-shooter timeline issue that plagued Desert Storm's Scud hunt would be difficult to resolve without a high-speed, long-range weapon targeted through the "grid" and released from an aircraft, surface ship, or submarine from a standoff range. Something analogous to Boeing's canceled Mach 5 Sea Lance from the mid-1980s comes to mind-capable of 100 nautical miles or so if launched from altitude or about half that if from a surface ship or submarine. Of course, reducing water entrance velocity in very shallow water would be a challenging engineering problem. The net effect would be a minefield-like affair where the sensors were distributed (and mobile) but the warheads were not. Sound waterspace management would control any friendly fire concerns, and the act of firing would be inhibited if a reported detection were at a location outside of the area announced as mined.
An alternative if the target is presumed to be operating in a constrained holding pattern could be a submarine-launched Mk 48-like weapon that would cruise to the target's expected vicinity at reduced speeds to conduct a detailed search of a defined area. On detection, the weapon would employ residual stored energy to attack at a higher speed. The energy-to-power ratio described above in the discussion of AIP submarine propulsion implies that there is enough stored energy in an Mk 48 torpedo to allow it to search for a week or more at 4-5 knots and still have enough residual energy for a high-speed attack. The launching submarine, meanwhile, could be employed in other critical tasks.
A tactical doctrine and sensor/weapons employment gap exists today, and different approaches must be taken to a very different ASW problem. The Air Force has neatly parsed the spectrum of air missions into five or six categories, two of which are defensive counterair and offensive counterair. Although a purist from the Air University at Maxwell Air Force Base in Alabama would contest such oversimplification, it seems that defensive counterair was what Spitfires and Hurricanes did during the Battle of Britain-attrition warfare in a target-rich environment. Offensive counterair was what Mustangs and Thunderbolts did over France after D-Day-bombed and strafed trains, bridges, and other infrastructure and forced the few remaining German Me-109 fighters to come out of hiding to contest such action-and get shot down.
Given the limited submarine experience of some potential opponents, particularly at higher command positions ashore, could it be likely that hunkered-down AIP submarines would be ordered out of hiding (and quickly use up their stored energy) to attack U.S. submarines raising hell from deep in their territorial waters? Have not senior commanders ashore often read in Proceedings that the best ASW platform is another submarine? Could there be an ASW variant of offensive counterair?
1 The wake-homing torpedo is a notorious exception to this general statement, as it is fired directly at the target with but one operator-derived input-whether to turn to the right or the left when the target's wake is detected, However, even though these torpedoes can run for many dozens of miles, most of this energy is expended while in a "tail chase" (especially against fast targets), and the range at time of fire is much shorter-requiring some positioning skills and expenditure of stored submarine energy in reaching the firing point.
2 Another sobering consideration is that in a network-centric warfare context, even relatively minor and casualty-free damage to topside sensors and communications gear could represent a mission-kill effect as great as the loss of a World War I or II battleship's main battery.
Captain Patton served in five nuclear-powered attack submarines and two ballistic-missile submarines, commanding the USS Pargo (SSN-650). On retirement in 1985, he established Submarine Tactics and Technology, Inc. He since has provided services to a number of government and private entities, served three years as the technical consultant to Paramount Pictures for The Hunt for Red October, and has participated in the annual major war games at the Navy, Army, and Air Force war colleges.