"Anti-Submarine Warfare is a core enduring
naval competency that will be a vital mission in
the 21st Century."
Admiral J.L. Johnson, Chief of Naval Operations



by John Morgan, Captain U.S. Navy

Anti-Submarine Warfare (ASW) remains the linchpin of sea control. With forward presence and expeditionary warfare rising to the top of Navy priorities under the “New World Order,” potential threats to our control of the intervening seas are increasingly unacceptable. And since the
submarine threat is among the gravest of these, effective ASW capabilities will be the sine qua non for our success in future crises and conflicts. This is no less true now than it was during the Cold War.

Despite the advance of technology, ASW remains a complex challenge with neither simple nor elegant solutions. Since the end of the Cold War and the subsequent decline in defense budgets, however, that challenge has become more severe. And yet, there are both promising technical and operational developments and a growing shift in attitude that deserve equal attention. Indeed,
current and near-term future developments augur well for greatly enhancing this important naval warfare area.

Today’s ASW Legacy
Like many other major issues facing today’s Navy, our current concerns about ASW trace back to the end of the Cold War and our subsequent redirection of emphasis toward potential conflict in the littorals. Our existing ASW capabilities are largely those that had been so painstakingly created to prevail over the Soviets in a global, deep-water conflict, and they are only partially adequate for the new and different environments we face today. Shallow water, near-shore oceanographic phenomena, asymmetric diesel and advanced Air-Independent Propulsion (AIP) submarine threats, and meager information about the potential battle space all contribute to significant uncertainties about our ability to contain the new and different undersea threat we face now. Further, since the Russian Navy has continued to build state-of-the-art nuclear submarines with global reach, the “Cold War” threat, though numerically smaller, remains to be countered also.

Yet today, ASW seems to some observers to be a tennis match with no opponent on the other side of the net. With the end of the Cold War and the simultaneous implosion of the Soviet/Russian navy, we are no longer seriously challenged at sea, except perhaps by local naval powers intent on acquiring modern submarine forces or new mine warfare capabilities. Consequently, we have not been able to practice ASW very realistically. Also, although our equipment has grown older and less effective, we have not noticed much impact, because the challenge has been so minimal. Nevertheless, the Navy’s ASW proficiency has declined in the last decade, and we must reassess future requirements and capabilities to meet an uncertain but still-dangerous threat.

The New ASW Assessment
Under the pressure created by a similar ASW crisis early in World War II, the Navy regrouped by establishing the Tenth Fleet to coordinate an integrated response to the threat. Within three years, the Allies had won the Battle of the Atlantic. Now, with the recognition that ASW challenges are steadily increasing world-wide, the Navy is regrouping again. With “coordination” and “integration” as key elements, the Anti-Submarine Warfare Division (N84) in the Office of the Chief of Naval Operations has been given a central responsibility for developing a requirements-based ASW plan, as a direct outgrowth of the Navy’s recent ASW assessment.

There are three fundamental truths about ASW. First, it is critically important to our strategies of sea control, power projection, and direct support to land campaigns. The Chinese military strategist Sun Tzu recognized some 2,400 years ago that the best way to defeat an enemy is to attack his strategy directly. As the United States looks to refine its focus on forward presence and power projection from the sea, as envisioned in the 1994 Forward...From the Sea strategic concepts paper, the submarine threat that denies, frustrates, or delays sea-based operations clearly embodies Sun Tzu’s dictum and attacks our strategy directly.

During the 1982 Falklands conflict, for example, the Royal Navy established regional maritime battlespace dominance with a single submarine attack, the sinking of the Argentine cruiser General Belgrano by the nuclear attack submarine Conqueror. But the British were fighting at the end of a perilously thin, 8,000-mile long logistics lifeline, and themselves were extremely vulnerable to submarine attack. Had the single Argentine Type 209 submarine that got underway, San Luis, been successful in just one or two of its several attacks — which were stymied as a result of an improperly maintained fire control system — and sank or seriously damaged one of the two British small-deck carriers or several logistics ships, the outcome might have been very different. We must recognize that in today’s and tomorrow’s conflict scenarios, the submarine is an underwater terrorist, an ephemeral threat. It will force us to devote a great deal of resources and time, which we might not have.

Second, ASW is a team sport — requiring a complex mosaic of diverse capabilities in a highly variable physical environment. No single ASW platform, system, or weapon will work all the time. We will need a spectrum of undersea, surface, airborne, and space-based systems to ensure that we maintain what the Joint Chiefs of Staff publication Joint Vision 2010 calls “full-dimensional protection.” The undersea environment, ranging from the shallows of the littoral to the vast deeps of the great ocean basins — and polar regions under ice — demand a multi-disciplinary approach, subsuming intelligence, oceanography, surveillance and cueing, multiple sensors and sensor technologies, coordinated multi-platform operations, and underwater weapons. Most impor-tantly, it takes highly skilled and motivated people.

Finally, ASW is hard. The San Luis operated in the vicinity of the British task force for more than a month and was a constant concern to Royal Navy commanders. Despite the deployment of five nuclear attack submarines, 24-hour per day airborne ASW operations, and expenditures of precious time, energy, and ordnance, the British never once detected the Argentine submarine. The near-shore regional/littoral operating environment poses a very challenging ASW problem. We will need enhanced capabilities to root modern diesel, air-independent, and nuclear submarines out of the “mud” of noisy, contact-dense environments typical of the littoral, and be ready as well to detect, localize, and engage submarines in deep water and Arctic environments.

Exercises with high-end diesel subs, such as the South Korean ROKS
Lee Jong Moo (SS-66), shown here with a P-3C and
Columbus (SSN-762) during RIMPAC 98, are vital to improving Fleet ASW proficiency.

The 1997 ASW Assessment gathered inputs from Fleet operators the intelligence and technical communities, and the Navy and Joint Staffs. The study team framed their effort by postulating several likely future ASW campaign scenarios involving U. S. coalition, and adversary forces and estimating the outcomes using both analytical and simulation techniques. Lessons learned were couched in accordance with the traditional responsibilities of the Navy Department to “train, organize, and equip” a navy. Strengths and weaknesses were identified in each area, with mixed results. The “good news” is that our equipment — the platforms, sensors, weapons, and C4I infrastructure planned for the coming decade — is quite good. Though much remains of the Cold War, deepwater legacy, it creates a solid foundation upon which to build the enhancements needed for effectiveness in the littoral, and new information processing technologies will help fill the remaining gap. On the other hand, today’s ASW training is deficient for reasons described above, and our command organization for coordinating multi-platform ASW and supporting it with Intelligence, Surveillance, and Reconnaissance assets ashore could be improved. In seeking to be better organized, the fact that our present approach is so platform-oriented is a major stumbling block.

The Way Ahead
Based on the findings of the 1997 assessment, the Navy is now developing a set of integrated ASW requirements, designing a mission architecture in response, and drafting a corresponding investment plan for the out-years. As the architecture, size of the force, and capabilities will be requirements-based, the starting point needs to be our best estimate of the submarine threat 15 years or so from now. At that time, a likely regional adversary may well be able to deploy 35-40 modern submarines in a mix of nuclear, diesel, and AIP types, most equipped with respectably modern sensors and weapons from the international arms market. In this light, and in a time of constrained resources, the overall ASW strategy most appropriate for future expeditionary warfare may well be some kind of “moving area control.” This would guarantee local undersea superiority or time-limited sub-free “havens” in areas of current interest, rather than the regional, if not global, superiority we sought during the Cold War. Thus, by successively concentrating forces and ISR assets only where needed for Sea Lines of Communication (SLOCs) or force protection, our forces can be focused optimally and their limitations at least partially finessed. The integrated ASW requirements, the mission architecture, and the long-range investment plan are all currently in work and will be updated continually to shape the Navy’s response to the evolving submarine threat.

Regrouping for Success
In retrospect, this period of the late 1990s will be viewed as a period of retrenching for ASW in the U.S. Navy. The new challenge is becoming clearer, and it is time to shift gears. Even though much of the Cold War threat is gone, the Navy has not failed to appreciate the future importance of ASW as a contributor to achieving the visions articulated in Forward...From the Sea and Joint Vision
2010. Other important policy documents — the Defense Planning Guidance (DPG) and the Navy’s Long-Range Planning Objectives — also call for a robust ASW capability that links warfare requirements to the real dangers and vulnerabilities introduced by the proliferation of next-generation submarines. Evidence of the Navy’s revitalization of ASW is beginning to accumulate.
For example:

Senior Leaders are Engaged.

  • The Chief of Naval Operations has testified before Congress that submarines and mines are among the most serious threats to the U.S. Navy. He chaired a CNO Executive Board (CEB) on ASW in July 1997. Along with Secretary of the Navy John Dalton, the CNO signed the 1997 ASW Assessment, which was forwarded to the Congress earlier this year. Excerpts from CNO’s more recent ASW “focus” statement are found in an accompanying sidebar. Most importantly, the CNO has led the way in providing stable funding for ASW accounts ever since he took office. Following up, Fleet Commanders are revamping ASW training and experimenting with new technology. There is a growing awareness by all echelons of the Navy’s leadership that the cycle of ASW is on the upswing.

Funding has stabilized.

  • Despite the challenge of ensuring today’s readiness while investing in the future, current funding projections show that the Navy is serious about modernizing ASW systems, sensors, and weapons.

New technology is continually being developed and fielded.

  • The Navy is experimenting with several new acoustic and non-acoustic technologies especially tailored to the littoral environment. A few examples include:

  • Distant Thunder. This is a new body of advanced signal processing techniques for shallow water, littoral environments that uses innovative computer processing to detect target echoes generated by low frequency active sources.

  • Interactive Machine-Aided Training (IMAT). This is an exciting new training approach that uses computer-generated visualizations of underwater sound fields and propagation phenomena to develop operator intuition and greater understanding of sonar conditions and sensor effectiveness.

  • Advanced Rapid COTS Insertion (ARCI). The submarine community is leading the way in introducing commercial off-the-shelf (COTS) computer technology into its ASW systems and sensors, and processing gains are dramatic. For example, when all ARCI builds are installed in an Improved Los Angeles (SSN-688I) attack submarine, that single SSN will command as much signal-processing power as the entire non-ARCI SSN-688 fleet at sea today.

  • Advanced Deployable System (ADS). ADS is a rapidly deployable, short-term undersea surveillance system designed for ASW monitoring of shallow water littoral operating areas. It will use an expendable, battery-powered, large-area field of passive acoustic arrays, interconnected and cabled to shore with fiber-optic cables.

  • Rapid Environmental Assessment. The Ocean-ographer of the Navy is developing techniques and procedures to assess the ASW environment of the littoral battlespace for rapid optimization of sensors and weapons and decision support. Remote offboard sensors and satellite signal processing play key roles.

  • Advanced Technology Demonstrations (ATDs). ASW projects have fared well in recent years in this important program that encourages high-risk projects that offer potential for high payoff.

The Navy is articulating more focused ASW requirements.

  • The undersea warfare community is pioneering a new approach to defining warfare requirements that uses a “systems integrator” process. While developing the budget, ASW program planners now treat the entire architecture as a whole, recognizing that effective ASW requires a chain of systems that can only be as strong as its weakest link. Future budgets will be determined by an investment strategy that seeks to strengthen the weak links while exploiting promising opportunities in training, organization, and technology.

Prospects for the Near Term
Despite this evidence of recent progress, there remain several shortfalls that could be addressed by additional near-term initiatives. Most notably, we are studying the creation of an ASW “center of expertise” at the numbered fleet level, which would hold responsibility for ASW training, the development of multi-platform coordinated tactics, and experimentation. This organization could have the power to control real assets — much as did Tenth Fleet in World War II — and certify each deploying battle group in integrated ASW proficiency that includes the exploitation of ISR assets, such as the Integrated Undersea Surveillance System (IUSS). We need regular access to an “adversary squadron” of modern diesel-electric submarines, and we ought to make maximum use of allied and friendly navies to fill the need, subsidizing them if necessary. As a “force-multiplier” for our limited platform assets, we should be looking at more commonality of ASW sensors and signal processors, with open, “plug-and-play” architectures that facilitate flexible applications on a variety of platforms. Finally, the U. S. Coast Guard’s “Deepwater” initiative for providing a “system of systems” for missions beyond 50 miles offshore — and which will include both a new “Maritime Security Cutter” and several aircraft types — may offer significant opportunities for littoral ASW mission and asset sharing.

Overall, ASW is finally emerging from a decade of atrophy. Acknowledging and understanding ASW’s recurring cycles of “boom-and-bust” can accelerate the awakening that is now underway in the Navy. We need to avoid any further unraveling that could permit the kind of devastating blows that history has shown can be fatal to a national military strategy that relies so heavily on unimpeded sea lines of communication. The Battle of the Atlantic in 1942-1943 and the Falklands War of 1982 have shown what is at stake.

A Rising Tide
ASW embodies the essence of sea control, which in turn remains the foundation for global power projection. The Chief of Naval Operations clearly understands the importance of both: “In fact,” as Admiral Johnson noted, “at the core of U.S. security requirements lies one prerequisite — sea control…. If we cannot command the seas and airspace above them, we cannot project power to command or influence events ashore; we cannot deter; we cannot shape the security environment.”

We are awakening to the demands and tasks ahead. There is renewed interest by the Navy’s leadership in core ASW competencies. Our intelligence services and operating forces are, once again, focused on the new generation of an old and familiar threat. Our technical community is addressing novel solutions to a complex, multi-faceted problem. In short, ASW is coming back. The greatest challenge now will be holding us “steady as she goes” on the course to recovery.

SURTASS ship USNS Able (T-AGOS-20)

Captain John Morgan is the Director, Anti-Submarine Warfare Division (N84), in the Office of the Chief of Naval Operations. A Surface Warfare Officer qualified in submarines, he has extensive multi-platform ASW operational experience.