A new dimension in ballistic missile defense came closer to reality when the Theater High Altitude Air Defense System (THAAD) achieved its first successful test in June 1999. Even with THAAD and other systems, however, hunting down missile launchers will still be an essential part of a total ballistic missile defense package.
We all have seen the headlines. Reading them, it would appear that we are on the verge of solving the challenge posed by theater ballistic missiles. If only Congress would commit adequate resources to Navy Theater Wide (NTW), Theater High Attitude Air Defense System (THAAD), or the airborne laser—and if only the hidebound ground commanders would allow free rein to the air campaign—the theater ballistic-missile threat would fade away. But such a view is dangerous.
Theater ballistic missile defense (TBMD) is a complex problem that will not end with a single solution. Success will rely on a multifaceted approach that emphasizes flexibility and diversity. The pillars of TBMD—attack operations, active defense, passive defense, and command, control, communications, and intelligence (C4I)—all are essential and will work only when employed in an integrated and synchronized fashion.
Two informal schools of thought have developed around the issue of conducting ballistic missile defense. The attack operations school argues that the technology to apply air power effectively is available today (or very close), and success requires only the refinement of C41 tools and the application of "military will." The opposing view—the active defense school—proposes a tiered system of interceptor missiles and/or lasers to shoot down the incoming missiles. This school suggests that attack operations never will achieve sufficient success, so defense must rely on layered active defenses.
Neither the proponents of attack operations nor those of the active defense school are simplistic enough to argue that the other pillars are totally unnecessary—but both schools tend to downplay each other's contributions, neglect passive defense entirely, and view C4I only as an enabler of their own pillar. More important, both schools fail to note their own limitations and recognize that cooperation between the pillars is essential.
The Attack Operations School
The inability of allied coalition air forces to prevent Scud launches or destroy Scud launchers was well documented in the Gulf War Air Power Survey. Nonetheless, the attack operations school holds that only the insertion of a relatively few technologies and the determination to press the air campaign home stand between this pillar and success. Here, the focus of operations shifts away from "Scud hunting," toward attacks on theater ballistic missile infrastructure or targeting the critical nodes identified in an effective intelligence preparation of the battlefield.
An operation taken in reaction to missile launches, Scud hunting is limited by simple time, distance, and speed calculations. When a missile is launched, there is a relatively constant delay inherent in satellite or radar detection, followed by a more variable delay while the decision is made to strike and the information is transmitted to a firing unit. Finally, a weapon must get to the launch site. If we assume that an aircraft is moving at perhaps 0.9 mach—or a mile every eight seconds—the problem takes shape. Even an aircraft only 30 miles from a launch site would take approximately four minutes to reach the target area. The cumulative delay in optimal circumstances is now perhaps six to ten minutes or more. By this time the Scud crew has driven to a predetermined hiding site and probably is well camouflaged. Much attention has been paid to determining refined launch points but this will do nothing to address latency.
Adding to the complexity of the problem is locating the launcher when the aircraft arrives in the launch area. The launch point itself is not a geographic point but an elliptical area of uncertainty. Once in the area, locating the launcher visually is extremely difficult, particularly at night. Illustrating the difficulty, 42 Scud launches were observed by attack aircraft in the Gulf War, yet only eight of the launchers were acquired visually by those same aircraft and attacked.
Certainly there are technical developments that will improve the chances of success. The ability to refine the missile launch point will help, and the development of a hyper-speed weapon—able to exploit that accuracy prior to the launcher's departure—has great potential. Predictive tools for launcher movement and expediting the decision and tasking process also will help, but the inherent time latency of reactive operations ensures that the contribution will be modest. More promising is the potential to cue airborne sensors (JSTARS [Joint Surveillance Target/Attack Radar System] or UAVs [unmanned aerial vehicles]), and the integration of an engagement grid consisting not only of tactical aircraft but conventional artillery, land attack missiles, and helicopters. These solutions, however, await resolution of both technical and doctrinal issues.
Nonetheless, post-launch prosecution of launchers is not the heart of the attack operations school. Instead, the school holds that if there were proper intelligence preparation of the battlefield the critical nodes necessary for theater ballistic missile operations could be identified, turned into targets, and destroyed within the air-tasking order cycle. These critical nodes include not only the launcher and its supporting vehicles in garrison, but also the road networks and other infrastructure permitting the mobility essential for launcher survival. This component of attack operations is known as "counter mobility" operations, and includes the use of conventional air-dropped ordnance, mines, unmanned ground sensors, and special operations forces.
In the fog of war, the probability of identifying all the critical nodes necessary to preclude missile launches is very low. The attack operations school also suffers from a tactical aviation focus. The potential contributions of artillery, naval fires, helicopters, and land attack missiles generally are not considered. Where time is vital, as in attack operations, this division is counterproductive and eliminates from consideration weapons that may be better suited to the task.
The attack operations school is not wrong, but it consistently overstates the probability of success, fails to consider countermeasures, and arbitrarily limits the weapons employed. Its probability of preventing all launches is about zero, so attack operations must be integrated with the pillars of active and passive defense.
Active Defense School
The active defense school of theater missile defense is more vociferous: if you listen to its rhetoric without critical analysis it is possible to envision an impenetrable iron umbrella over friendly forces. Yet active defense is not a silver bullet, and cannot provide adequate protection alone.
Stripped of rhetoric, how well do the intended systems work? Navy Area Defense, for example, is not misnamed. It is a system designed to protect a limited geographic area against a defined threat missile type—like Patriot and THAAD. The operational commander cannot expect to provide theater coverage and can anticipate difficulty with missiles whose performance exceeds that of the defined threat category.
The SM-2 Block IVA (like Patriot PAC-3) is an endoatmospheric interceptor with a fixed maximum velocity, designed to intercept a ballistic missile within finite minimum and maximum altitudes. A long-range ballistic missile is less a short-range missile that travels farther than one that travels faster. In short, the faster the missile, the smaller the area that can be defended—until finally the likelihood of intercept becomes problematic.
Very short-range theater ballistic missiles also can present problems. The short duration of the flight itself may not allow sufficient time for an Aegis ship offshore to detect and engage the target. The limitation is the velocity of the interceptor, which cannot in all cases reach the missile prior to impact. For the Navy, this is a particularly important consideration following the Marine Corps' decision to decommission the Hawk and the uncertainty over fielding the Medium Extended Air Defense System.
With endoatmospheric interceptors such as Patriot and Navy Area Defense, rarely will there be enough time for a traditional shoot-look-shoot type of engagement. The narrow window requires firing whatever salvo is chosen with rounds launched as close together as technically feasible. Even when integrating a system like THAAD with a lower tier system, theater ballistic missile velocity may not permit evaluation of the success of THAAD prior to a decision to employ the lower tier system. Thus two-tier coverage provides better protection, but rapidly depletes inventory.
Target discrimination, or determining which of the objects reentering the atmosphere contains the warhead, is a difficult technical challenge and one that also impacts inventory directly. The discrimination problem arises not only from decoys or penetration aids, but from phenomena associated with the launch (e.g., the discarded stages). In an ideal world we would launch a single interceptor at the re-entry vehicle containing the warhead. However that clarity may be absent, resulting in a decision to expend multiple interceptors at unclear targets.
The programmed procurement of the Navy lower-tier interceptor, the SM-2 Block WA (a missile effective against both theater ballistic missiles and air breathing targets), may be as low as 750 missiles. That will mean roughly 375 each for the Atlantic and Pacific Fleets, less those expended in testing, those not ready for issue or in maintenance, and those transiting to or from the theater. A cursory comparison of the missiles available (assuming a salvo of two-to-four interceptors per target) with the number of theater ballistic missiles postulated for North Korea (or China) brings the practical limits of active TBMD into focus.
NTW, designed for exoatmospheric intercept, will allow the intercept of missiles during ascent and midcourse phases and will provide a marked increase in capability. But even this has limits. The difficulty lies in a ship's potential assignment to cover geographically separate points with a multiple-salvo doctrine. As the launch area expands, the ship must pull back toward the defended area, lessening and eventually eliminating the opportunity for ascent phase intercepts—thereby compressing the defended area. Similarly, the requirement to engage with two or more missiles is prudent tactically but also compresses the defended area. In a geographically limited area like Korea this is manageable, but where NTW ships are forced to defend against widely dispersed launch points this has a dramatic effect on coverage. Discrimination remains a difficult problem. The interceptor—the SM-3—will be an expensive missile, and NTW capability will be taxed with deployment requirements around the globe.
Like the attack operations school, the active defense school is not wrong—but it overstates its role by ignoring countermeasures and the practical limitations of geographic coverage and interceptor inventory.
The Path to Successful TBMD
To be successful against the challenge of mobile theater missiles, the operational commander must have a flexible, dynamic, and integrated concept of operations and the technical means to translate this vision into action. The concept of operations and implementing tools must be flexible enough to accommodate the evolution of enemy tactics and weapons. They must be capable of adjusting to inevitable losses and accommodating changes caused by political considerations, an unanticipated opponent, or restrictions on rules of engagement.
The concept of operations and C41 architecture must be dynamic enough in capability to recognize that war is uncertainty. Rigid doctrine or reliance on inflexible technical solutions will not permit the operational commander to adjust to inevitable changes. The concept also must be dynamic enough to recognize the role of tempo and shifts in the relative importance of targets and defended areas.
Integration does not refer to simple interoperability of systems, but instead to the integration of effects. It is the recognition that a diminished inventory of active defense interceptors must alter the tempo of attack operations and passive defense posture. It is the knowledge that the movement of a company of Marines or the arrival of a supply ship in port in some way alters the nature of the theater ballistic missile battle. These changes occur within minutes, and any concept or plan must have the organizational and technical integration to adjust accordingly.
Attack Operations
The goal of attack operations is not to destroy launchers, but to prevent an opponent from launching missiles. This can be accomplished in four ways: attack operations can be launched against the ballistic missile infrastructure; operations can be undertaken against road networks to limit the mobility of mobile launchers; attacks can be launched against time-critical targets such as launchers, fuel trucks, or related targets; and increased operational tempo can disrupt enemy timing.
Successful operators must employ counter-infrastructure, counter-mobility, time-critical targeting, and counter-tempo attack operations in an integrated fashion. The integration of special operations forces, airborne intelligence, surveillance, and reconnaissance assets, conventional artillery, tactical aviation, Army helicopters, and land attack missiles—among other things—necessitates breaking down the existing stove-piped command relationships and developing common doctrine and technically interoperable C41 Systems.
The "Ring of Fire" concept' contains the essence of how a network can be created to address such time-critical targets as Scud launchers. For example, a sensor in a sensor grid detects and identifies a launcher. This information enters a distributed network, controlled by a common algorithm, where a weapon is paired to the target and tasking is sent to the firing unit. If further sensor confirmation is needed or weapons are not available, that same algorithm may direct a sensor toward that target.
The algorithm calculating the best response to the cued information controls the automated weapon or sensor to target pairing. Targeting data and force orders are passed directly to the shooter and the operator launches the attack. The pairing algorithm must—at a minimum—consider the priority of the target, weapons available, confidence in correct target identification, probability of success, risk to the firing platform, and airspace clearance.
Effective employment of a Ring of Fire-like concept will demand substantial changes in doctrine, methods of command and control, and technology. Proceeding from a shared vision to the construction of the controlling algorithms and determining the degree and location of human interface will be a challenging process, and will require new levels of jointness. But if attack operations are to succeed, such a sea change is required.
Active Defense
Active defense relies on a dynamic planning process that must determine what is to be protected by limited assets and how well each of those prioritized areas will be protected.
A networked solution, including the ability to conduct composite tracking (through netted sensors) and coordinated engagements, increases options and enhances effectiveness. In general, tracking across wider portions of the electromagnetic spectrum complicates countermeasures and increases accuracy and flexibility. Netted sensors—radar, infrared, and others—could provide a more consistent air picture and assist in target discrimination and reentry-vehicle identification. A coordinated engagement capability consists of overlapping engagement zones, upper- and lower-tier redundancy, and the C41 to conduct real-time force orders, kill assessment, and dynamic retasking. This integration will optimize weapons performance, while conserving inventory.
In a networked scenario, a ballistic-missile launch is detected initially by satellite-based infrared sensors or by radar. Through a distributed network, this cues additional sensors. In the case of radar, this cue allows the sensor to conserve available energy by limiting the scope of its initial search. A composite track is established as units share measurement data. Composite tracking takes advantage of the differences in sensor frequency, while distributed sensors take advantage of the differing aspect or radar cross-section. Highly accurate track data, launch, and impact points are generated and transmitted to nonparticipatory nodes. A distributed algorithm considers intercept geometry, velocity, countermeasure resistance, available inventory to determine probabilities of kill and calculates optimal weapon-to-target paring. One or more firing units receive the force order along with recommended number of missiles to be fired, the desired intercept altitude, and other information. Combat losses, another launch, or a failed intercept would dynamically spur additional responses, and force orders would be altered accordingly.
A networked engagement grid, as described, demands fully integrated technical and doctrinal solutions based on a shared vision of the battle. But if joint forces are to advance beyond the simplistic and inventory wasting system of sectoring the battlespace or arbitrarily dividing responsibility in time segments, this level of joint coordination and integration is required.
Passive Defense
The process of posturing forces to reduce vulnerability and minimize the effects of ballistic missile impact constitutes the least glamorous pillar of theater missile defense. For the foreseeable future, however, it will remain essential. Passive defense is not just a timely warning when attack operations and active defense fail, but also the preparation that occurs before the launch—or even before the campaign. Effective passive defense will be built on the realization that no system of defense is perfect. Some assets will be unprotected; launches will occur; and some missiles will penetrate defenses.
Early warning and a protective posture are important, but obviously, avoiding attack altogether is the preferred option. Avoiding attack can be accomplished by deceiving enemy targeteers through deception or concealment. It also can be attained by the tactical decision to reduce vulnerability by remaining in an active defense shadow, or by pulsing sortie rates to restrict missile launches. However, this implies a situational awareness and knowledge of the capabilities and limitations of the coordinated TBMD effort by commanders at the operational level and below, and demands connectivity between nodes as disparate as troops in the field and major logistic force commanders.
If joint forces realize the limitations of the other pillars, they are better postured to take proper actions to minimize the probability of being attacked and the destructiveness of a potential impact. Ideally, each unit on the battlefield should know its own relative vulnerability in order to take appropriate countermeasures. Each command element should know the relative threat posed to subordinate units and should have a rapid means to communicate that to the air defense decision makers. This again implies a network whose products could then be used (or not used) to influence the conduct of attack operations or the deployment of active defense forces.
C4I—The Critical Linkage
The answer to successful TBMD ties only in accepting that there is no silver bullet and developing an effects-based concept of defense—the product of a dynamic interaction between attack operations, active defense, and passive defense.
Evolving defensive requirements will lead to changes in the method and degree of protection required. Dynamic retasking also will be required at the tactical level during battle. For example, as interceptor inventory is depleted on an individual ship, other units may need to engage, with perhaps a lesser probability of kill. This in turn may lead to an altered salvo doctrine, a decision to move other firing units, re-tasking aircraft and an altered protective posture. In a massed raid, this dynamic retasking will have to occur in the midst of the raid itself.
Networked sensors and engagement grids will improve the tactical effectiveness of weapon systems, and when they are coupled with networked, collaborative intelligence the result will be a synergistic relationship between the various pillars. Attack operations will shape the battlespace by targeting infrastructure, limiting mobility and controlling the tempo of operations. Passive defenses could employ information operations or dispersal to draw fires into areas to minimize damage, deplete theater-ballistic-missile inventory, and to cue the attack-operations sensor and engagement grids. Active defenses could take advantage of reduced protective responsibilities and limited intercept geometry to mass assets and provide enhanced protection where really needed. In this scenario, commanders will not merely react to enemy moves but also will anticipate actions and modify defensive posture to best defend their forces.
The first step is to recognize that a gas mask, an F- I 5E, a JSTARS, a special-operations reconnaissance team, an early-warning net, and an Aegis cruiser are all essential to successful TBMD. Only if these elements are integrated can a commander realize the breadth of options and harness the synergy required to prevail against this challenging threat. The broader the front, the more difficult it will be for any potential opponent to devise a scheme to overcome defenses. Arguments for one approach at the expense of another ultimately will prove counterproductive. Technical solutions that do not accept the absolute requirement for integration are a wasted investment, no matter what the individual systems' capabilities.
So the next time you read a headline touting a TBMD system, remember that some theater ballistic missiles always will launch and some of those always will get through. Until that elusive silver bullet is found, we will be forced to integrate our efforts to lessen the number launched, attrite as many of those in flight as we can, and prepare for the one that inevitably will get through.
Commander James is a surface warfare officer assigned to the Navy Warfare Development Command in Newport, Rhode Island.