Defining the "Precision Weapon" in effects-based terms.
Armaments (Usage)
Military maneuvers (Analysis)
Sine, Jack
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Name: Air & Space Power Journal Publisher: U.S. Air Force Audience: Trade Format: Magazine/Journal Subject: Military and naval science; Science and technology Copyright: COPYRIGHT 2006 U.S. Air Force ISSN: 1555-385X
Date: Spring, 2006 Source Volume: 20 Source Issue: 1
Event Code: 440 Facilities & equipment
Product Code: 3480000 Ordnance & Accessories; 9103561 Military Action; 9104132 Military Exercises & Maneuvers NAICS Code: 33299 All Other Fabricated Metal Product Manufacturing; 92812 International Affairs; 92811 National Security SIC Code: 3480 Defense industries
Government Agency: United States. Air Force
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Editorial Abstract: According to Major Sine, as technology evolves, war fighters and planners need to expand the concept of weapons effects beyond merely destructive results and develop an inclusive definition of precision weapons tailored to effects-based operations. He proposes a definition that focuses specifically on the preciseness of the weapon's effect rather than on the meaning of "precision" as it relates to the accuracy of a weapon's guidance system.


DURING A RECENT Pentagon discussion of weapons programs and future requirements, an Air Force flag officer asked for clarification of the term precision weapon: "Is precision three-meter accuracy, or ten-meter, ... or is that accurate?" The question initiated a long debate that was never resolved but did draw attention, not only to the confusion generated by the current use of the term, but also its inadequacy in light of emerging technologies.

Today conventional wisdom considers a weapon "precise" if it possesses the capability to guide to a specific aim point. However, as technology evolves the concept of weapons effects beyond merely destructive results, war fighters and planners require a more inclusive definition tailored to effects-based operations (EBO). A doctrinal definition for precision weapons must be applicable to the wide range of force-application capabilities available today and in the future. In addition, the preciseness of the weapon must be calculated considering all variables associated with weapons employment, including navigation accuracy, weapons effects, undesired effects, and potential unintended effects.

This article proposes that a precision weapon be defined as a tactical capability providing measurable and quantifiable first-order effects and minimal unintended or undesirable effects. The intent is to focus specifically on the preciseness of the effect the weapon achieves and not the precision that relates to its guidance-system accuracy. This article will not explore the more abstract concepts of precision engagement and precision attack.

Defining the Problem

Historically, weapons employment tied bomb quantities to target destruction. During World War II, airmen applied the term precision to weapons aimed with the Norden bombsight. In 1943 this definition of precision equated to a circular error probable (CEP) of approximately 1,000 meters, which required more than 1,500 sorties and 9,000 bombs to achieve a single objective. (1)

Currently, the USAF Weapons School focuses its definition of precision on the accuracy of the guidance system by teaching that a precision weapon impacts within a three-meter CEP as compared to an accurate weapon, which hits within a 10-meter CEP. (2) These are not, however, official USAF definitions. Rather, the Joint Direct Attack Munition (JDAM) operational requirements document coined these terms for its two JDAM guidance-kit variants. It stated that the "results of the Precision Strike Capability/JDAM PIP [Performance Incentive Program] Accuracy Requirements Study, 15 November 1994, support the 3 meter and 13 meter CEP for the precision and accurate guidance kits, respectively" (emphasis added). (3) Although originally stated as a 13-meter CEP, accurate has acquired a more nominal 10-meter CEP in its usage at the weapons school.

However, associating precision with guidance accuracy addresses only one aspect of weapons targeting and employment. After Operation Desert Storm, airpower advocates trumpeted the evolution of weapons technology that could produce a one-to-one ratio of bombs dropped to targets destroyed. The relationship of precision-guided munitions (PGM) to operational planning implied precision in terms of economy of force. In simple terms, a precision-guided weapon provided more than just destructive results; it ensured a tactical effect with just one or two weapons.

New weapons used later in Bosnia, Afghanistan, and Iraq, however, produced effects that went well beyond the one-to-one target-to-bomb ratio. The Air Force used several weapons without terminal guidance that produced precise effects. For example, a carbon-fiber munition used in Bosnia accomplished exact, desired effects and little collateral damage without any form of self-guidance. (4) Likewise, six unguided, sensor-fused weapons released multiple precisely fused submunitions in Operation Iraqi Freedom that killed 45 vehicles. (5) These cases demonstrate the limitations of relating precision to either guidance accuracy or target-to-bomb ratios.

As the concept of EBO matures, destructive effects become just one of many potential weapons effects. Directed-energy, nonlethal weapons, and even virtual-world weapons such as computer viruses open the aperture of weapons effects. In light of these rapidly advancing technologies, we must provide the term precision weapon with a consistent definition that will be relevant and accurate as weapons continue to evolve.

Effects and Precision

The Gulf War ushered in a new paradigm for the application of airpower: operational planners targeted the key nodes of a system to achieve desired objectives rather than target an entire system for destruction. For example, in targeting the Iraqi Integrated Air Defense System (IADS), planners designated desired mean points of impact (DMPI) that, when struck, would disable the command and control functions of the sector operations centers (SOC). As a result, war fighters met the operational objective of disabling the sector IADS without having to destroy an entire SOC. The planners were able to reduce from eight to two the number of 2,000-pound PGMs directed at each SOC on the first night of the war. Not only did this achieve the desired effect, but it released an enormous amount of firepower to concentrate on other critical systems. (6)

Air Force Doctrine Document (AFDD) 1 defines this as effects-based operations, "actions taken against enemy systems designed to achieve specific effects that contribute directly to desired military and political outcomes." (7) More specifically, "Effects-based actions or operations are those designed to produce distinct, desired effects while avoiding unintended or undesired effects." (8) Through EBO, Gulf War planners endeavored to accomplish multiple high-level results: create the effect of mass through precise application of force, economize force through a reduction of required sorties per objective, and reduce unintended and undesired effects.

Effects, rather than destruction, have become the template for war planning. Col Timothy Sakulich, in his paper Precision Engagement at the Strategic Level of War, describes four classes of effects outlined in the Institute for Defense Analysis' Joint Advanced Warfighting Project (JAWP): desired effects on enemy capabilities, desired effects on enemy assessments and actions, undesired effects, and unexpected effects. (9)

Desired effects on enemy capabilities equates to the obvious, intended effect. In their article "Dominant Effects: Effects-Based Joint Operations," Edward Mann, Gary Endersby, and Tom Searle break this definition out further into direct effects, or first-order effects, and indirect effects, or second-order and third-order effects. Desired, direct effects are measurable and tend to be obvious immediately, such as destroying a power generator. Desired, indirect effects occur through a linked system of cause and effect, such as disabling water pumps and purifiers by destroying the supporting power generator. (10) Desired effects on enemy assessments and actions refers to second- and third-order effects on the enemy's decision-making process. For example, repeated attacks against operating power plants in Baghdad led power-plant managers to shut down operating generators to avoid further attack. (11) These effects do not necessarily occur through a formal, structured system and may or may not be measurable or predictable. Undesired effects equate to collateral damage and may be first-, second-, or third-order effects directly or indirectly related to the desired effect. Unexpected effects may be first-, second-, or third-order effects related to the desired effect but not predicted in relation to the desired effect. For example, Desert Storm critics attributed 40,000-100,000 civilian deaths to water-supply interruptions caused by destruction of Iraqi electrical production. (12) These deaths were both undesired and unexpected.

Weapons employment produces first-order effects and relies on a system of cause and effect for second- and third-order effects. Target development includes responsibility for ensuring second- and third-order effects by determining enemy-system characteristics and targeting appropriate points within the system to achieve desired effects. Therefore, the target developer becomes responsible for predicting desired and undesirable effects associated with a given weapon-target pairing as well as reducing unexpected effects as much as possible. This describes EBO in accordance with AFDD 1: "EBO requires airmen to think through the full range of outcomes, choose those that will best achieve objectives, and find ways to mitigate those that will impede achieving them." (13)

Collateral damage plays a significant role in this process. Protocol I of the Geneva conventions directs forces to "refrain from deciding to launch any attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civil objects, or a combination there of, which would be excessive in relation to the concrete and direct military advantage anticipated." (14) While there is much room for interpretation in the protocol, it essentially ties, or at least shares, the responsibility for unintended or undesired effects to the attacking force.

Michael Lewis offers his personal account as a USAF judge advocate general (JAG) scrubbing target lists during Desert Storm to ensure coalition compliance with the laws of armed conflict. He describes a "proportionality analysis" performed for each target that accounted for "accuracy of weapons, the aim[ing] points that had been selected by the aircrew, the proximity of civilians, and the military value of the target." (15) Precision-guided weapons simplified this analysis by producing more predictable results: "Individual [command, control, communications, and logistics] set attacks might be judged, in retrospect, to have failed the proportionality test, particularly where no precision-guided munitions were used against high civilian targets that were not time critical." (16) For Lewis, PGMs produced a predictable and measurable effect, which facilitated targeting and alleviated legal and operational concerns by producing consistent, predictable, first-order effects and minimizing undesired effects.

Undesired effects play an increasingly critical role in war planning. Desert Storm analysts coined the phrase "CNN effect" to describe the sometimes disproportionate degree of attention given to undesired or unexpected effects. In their article "The Evolving Battle- field," John Foster and Larry Welch state that "every incident of unintended destruction against noncombatants became an object of press, public, and political attention." (17) The CNN effect not only highlighted undesired effects but arguably added second- and third-order undesired effects that would not have existed otherwise.

The CNN effect forced mission planners to understand enemy-system characteristics to anticipate and minimize the undesired effects or risk having those undesired effects magnified by near-real-time media coverage. Precision weapons, of whatever type, provide planners the ability to predict second- and third-order effects more reliably while reducing undesired and unexpected effects.

Analysis performed by JAGs in combat as a part of the targeting process highlights the influence of scenario on weapons employment. During Operation Allied Force in Kosovo, pilots often had difficulty identifying vehicles on the ground as enemy or noncombatant. The issue had become so serious and sensitive that coalition participants involved in the targeting process vetoed missions for collateral-damage concerns. Gen Wesley Clark commented, "We needed to know what was inside of the trucks. When we couldn't find out, we stopped bombing trucks." (18) The weapons available could not achieve desired tactical objectives without an unacceptable level of collateral-damage risk--killing civilians and/ or destroying their vehicles. Interdiction efforts against enemy truck supply were then further restricted by severe rules of engagement because of the lack of intelligence and lack of weapons precise enough to produce the effect without a corresponding unacceptable risk.

One argument contends that the coalition forces had kinetic-kill PGMs available but that intelligence was not sufficient to employ the weapons without risking undesired effects. However, in the fog and friction of war, users often lack the fidelity of intelligence required for the available weapons. If, on the other hand, the coalition had possessed a precision weapon capable of incapacitating a truck without injuring personnel inside or in the vicinity of the truck, planners would have been able to continue the interdiction campaign. For example, a nonlethal weapon, such as an electromagnetic pulse weapon, might have been capable of producing the tactical effect without the undesired effects associated with explosive weapons. In this scenario, the operational effectiveness of a laser-guided bomb (LGB) approaches zero, since rules of engagement generally did not allow operators to employ it. A nonlethal weapon, on the other hand, might have provided war fighters with the capability to meet their tactical objectives without risking undesired effects.

What Do Precision Weapons Deliver?

How does a tactical-level planner determine the most precise weapons for employment in the EBO construct? Based on the current use of the term precision weapon, war fighters make a comparison of guidance accuracies--the weapon with the smallest CEP is considered to be the most precise. In that discussion the term PGM is more appropriate because that acronym points to the attribute that is being described as precise--weapon-guidance capability. As in the interdiction efforts of Allied Force described above, LGBs and other PGMs may rightly be viewed as imprecise weapons.

Gen Ronald Fogleman, former USAF chief of staff, observed, "It is easy to quantify the effects of air power at the tactical level; for example, how many trucks and how many tanks are destroyed. These are results we can measure and compare with results from other weapons." (19) So at the tactical level, a more precisely guided munition possesses the attribute of being more likely to accomplish the tactical objective than a less precise weapon. One metric for determining the preciseness of a weapon is the number of tanks and trucks destroyed per weapon.

However, collateral damage affects the assessment of precision as well. During Desert Storm, tactical planners used PGMs to attack the Al Firdos bunker in Baghdad. Planners set a tactical objective of neutralizing the command and control functions that had moved into the facility. Unbeknownst to intelligence, JAG, or planning personnel, the Iraqi military members working in the bunker moved their families into the facility as well. The weapons employed achieved the tactical, first-order effect as planned. However, the first-order undesired effect was staggering: women and children killed by the same bombs. (20) Had it been known that civilians were present deep inside the bunker, the tactical planners may not have chosen to use those precision-guided bunker penetrators for their attack, or the JAG may have recommended against the bunker attack altogether so as not to put the civilians at risk.

In this case, precision-guided weapons produced direct, desired effects as planned but did not offer enough precision to prevent civilian deaths. Again, critics may attribute unexpected effects to deficient intelligence. However, had a weapon been available to isolate the command and control functions from the battlefield without damaging or lethal effects, intelligence on potential undesired effects would not have been necessary.

Undesired effects reduce the precision of a weapon by reducing the overall tactical effectiveness. A 500-pound, laser-guided weapon may be considered precise against a static artillery piece sitting in the open desert--it has a high probability of killing the target, eliminating the possibility of its future use against friendly forces, and has little probability of causing an undesired effect. However, that same static artillery piece parked in a crowded market reduces the precision of the same 500- pound, laser-guided weapon due to the potential for undesired effects. In an abstract sense, the probability of successfully achieving the effect of neutralizing the artillery piece becomes zero for this weapon-target pairing since collateral-damage risks will most likely prevent the use of this weapon in this scenario.

While precision weapons should be thought of in relation to their first-order, tactical-level effects, their use also creates implications and expectations at the operational and strategic levels of war. PGMs in an operational context offer high probabilities of delivering tactical effects, thereby reducing sorties required per objective. As a result, more objectives may be met in the same amount of time while simultaneously shrinking undesired effects. The U.S. Air Force Transformation Flight Plan (2003 edition) states that because of PGMs, "the U.S. doesn't need to deploy as many forces (air, sea, and ground) to achieve the same capability and, thus can deploy more rapidly.... The same number of forces ... can strike many more targets successfully than a force without precision-guided munitions, enabling orders of magnitude improvement in overall firepower." (21)

The level of precision, however, is scenario-dependent. Both LGBs and carbon-fiber munitions are capable of meeting the tactical objective of degrading the Serbian electrical supply. The latter may require more revisits to ensure lasting effects--a negative at the operational level. However, the former may produce intolerable, undesired effects by destroying Serbian infrastructure--a greater negative at the strategic and policy levels. The target planner weighs the relevant variables and chooses a solution, the most precise solution, for the scenario.

Precision weapons seldom produce direct, strategic effects, but their impact at the strategic level contributes to the definition of a precision weapon. Likewise, at the operational level, a precise weapon offers the capability to deliver a strategic effect simultaneous to the tactical effect. A single bomber delivering a weapon directly into Saddam Hussein's hiding place might have ended Iraqi Freedom before it started. The Gulf War Air Power Survey claimed, "Precision weapons [PGMs] that had heretofore primarily provided tactical advantage were used in the Gulf conflict to pursue operational and strategic effects throughout a theater of war." (22)

However, PGMs only provided the tactical first-order effect. The predictability and consistency--the technical exactness--of precision weapons allowed operational planners to simplify the characterization of the system of cause and effect and undesired effect by eliminating many of the variables that less precise weapons present. Sun Tzu professed, "The general rule for the military is that it is better to keep a nation intact than to destroy it.... Therefore, those who win every battle are not really skillful--those who render the others' armies helpless without fighting are the best of all." (23) A precision weapon, which may or may not be a PGM, provides a tool within the EBO construct to render the enemy army helpless without destroying the nation supporting it.

The Definition

A doctrinal definition of precision weapon must ensure clarity in the use of the term while preventing an oversimplification of the concept. Sakulich argues that current use of the terms precision engagement and precision strategic application misrepresents the capability of the military planner to predict strategic effects from tactical effects. He recommends that "doctrine clearly differentiate technical exactness from strategic correctness." (24)

A standard dictionary defines precision as "EXACTNESS ... the degree of refinement with which an operation is performed or a measurement stated." In the context of weapons employment, this definition implies two qualities. First, precision accomplishes the exact, desired effect with minimum undesired or unintended effects. Second, precision provides for measurability. To compare preciseness among weapons solutions, the degree of preciseness must be measurable.

The definition of precision weapon must include technical exactness, including weapons that deliver effects by other than kinetic means. Technical exactness implies a predictability of effect, assuming correct functioning of the weapon. Compare the effects of a 500-pound bomb versus a canister of flyers urging enemy combatants to surrender. Planners can be very certain of the effects caused by the blast and fragmentation of a bomb; however, they cannot be as certain of the number of enemy combatants that will surrender as a result of the flyers dropped over a battlefield.

Technical exactness also implies a measurability of effect. Joint Publication 3-60, Joint Doctrine for Targeting, states that "the art of targeting seeks to achieve desired effects with the least risk, time and expenditure of resources." (25) The preciseness of a weapon can be determined by comparing its contribution to reducing these factors for the planner. And to compare the preciseness of one weapon to another, the impact on each of these factors must be measurable.

Implicit in the measurability of the effect of a precision weapon is the ability to assess the effects of the weapons. Defense Intelligence Agency (DIA) analysis of the results of 2,000- pound LGBs dropped by F-117s and F-111Fs during Desert Storm determined that, despite the accuracy of the deliveries, each of the DMPIs targeted by these weapons had been struck by multiple LGBs. The analysis found that in the absence of timely battle damage assessment, planners targeted DMPIs multiple times despite the accuracy and predictability of the weapons used. While the function of the weapon did not contribute to the lack of assessment in this case, the end results are analogous: more weapons were employed than were required. The point is not that intelligence is required to determine preciseness; rather, the effects of the weapon have to provide for assessment. As in the flyer-bomb example above, the preciseness of a weapon cannot be determined if the effect of the weapon cannot be assessed.

A myriad of situational variables makes a weapon more or less effective. Target vulnerability, effect desired, weather, intelligence, environment, and proximity to sensitive areas may make the same weapon suited or not suited for a target. These observations lead to the conclusion that for a weapon, precision depends on the scenario. For example, the lack of a capability to identify the status of vehicles in Kosovo created a requirement for precision beyond the capability to guide a kinetic weapon to a specific point.

The effects produced by a precision weapon provide for a quantifiable assessment of undesired effects. Again, limiting the concept of a weapon to tactical, first-order effects, the planner must be able to compare the potential undesired effects as well as the desired. In the case of kinetic weapons, the blast and fragmentation patterns are measurable and predictable. The planner understands that personnel and objects within that pattern will experience the same effects as the desired aim point. In the case of nonlethal weapons, the weapon may produce a wider field of effect than a kinetic weapon, but since the effect is nonlethal or perhaps even nondamaging, it may be the more precise weapon for that particular application.

The inconsistent and ambiguous nature of the battlespace prevents us from defining any particular weapon as universally precise. The proper use of the term precision weapon must include the context within which the weapon will be employed to include the target, its environment, the desired and undesired effects, and the rules of engagement. A weapon becomes a precision weapon when it provides the means of causing a specific, measurable tactical effect while minimizing undesired effects. Dependent on scenario, this effect must be quantifiable, assessable, and predictable.


This article does not propose any change in the targeting process. Rather, it proposes a doctrinal definition for the term precision weapon. The misuse of this term leads to incorrect categorization of weapons and over-simplistic comparisons of weapons capabilities. To combat this, war fighters and decision makers must first recognize that PGMs and precision weapons are not synonymous. Second, breaking the direct relationship between guidance accuracy and precision will help prevent those unfamiliar with these more complex targeting subtleties from incorrectly categorizing weapons or simplifying employment decisions based on oversimplistic comparisons.

Operational and tactical planners should thoroughly understand the desired effects and undesired effects associated with each of the weapons available for use. Tactical planners do not require a separate term to distinguish between a weapon with three-meter CEP and one with 10-meter CEP. Operational and tactical planners, however, do require the ability to associate a level of effectiveness to a particular weapon in a particular scenario.

At the strategic and force-planner level, this definition of precision weapon will help to prevent confusion and misinterpretation among decision makers who may not be as experienced or familiar with weapons or military effects. Ideally, this definition will prevent the decision makers with budgetary balance sheets in front of them from striking through a weapons system merely because it does not include the word precision in its nomenclature.

As a doctrinal term, precision weapon may be applied across the wide range of military applications but must reference the tactical, first-order-of-effect level. This term used consistently in proper context will reinforce the concept of effects-based planning. Joint Publication 3-60 quotes Polybius: "It is not the object of war to annihilate those who have given provocation for it, but to cause them to mend their ways." (26) Precision weapons provide the consistent, predictable, first-order effects required for the future of effects-based operations.


(1.) CEP is defined as the distance from the aim point within which 50 percent of the weapons will impact. See Joint Publication 1-02, Department of Defense Dictionary of Military and Associated Terms, 12 April 2001. The U.S. Air Force Transformation Flight Plan (Washington, DC: HQ USAF, Future Concepts and Transformation Division, November 2003), 61, AF_TRANS_FLIGHT_PLAN-2003.pdf.

(2.) Maj Brian "Hack" Jackson, USAF Weapons School instructor, telephone interview by the author, 19 November 2004.

(3.) JOINT CAF and USN Operational Requirements Document (ORD) for Joint Direct Attack Munition (JDAM) Program (U) (Langley AFB, VA: Headquarters Air Combat Command/ DRPW, 1995).

(4.) The USAF employed a cluster munition that released carbon fibers to shut down electrical power plants during Operation Allied Force. See Michael W. Lewis, "The Law of Aerial Bombardment in the 1991 Gulf War," American Journal of International Law 97, no. 3 (July 2003): 507.

(5.) Briefing, Mr. Bob Allison, ACC/DRZW, USAF Munitions Working Group, Langley AFB, VA, subject: Area Attack Munitions, 15 September 2004.

(6.) See Edward Mann, Gary Endersby, and Tom Searle, "Dominant Effects: Effects-Based Joint Operations," Aerospace Power Journal, Fall 2001, 92-100, http://www.airpower. html (accessed 19 July 2004).

(7.) Air Force Doctrine Document (AFDD) 1, Air Force Basic Doctrine, 17 November 2003, 98.

(8.) Ibid., 18.

(9.) Timothy J. Sakulich, Precision Engagement at the Strategic Level of War: Guiding Promise or Wishful Thinking Occasional Paper no. 25 (Maxwell AFB, AL: Air War College, December 2001), 11.

(10.) Mann, Endersby, and Searle, "Dominant Effects," 99-100.

(11.) Lewis, "Law of Aerial Bombardment," 486.

(12.) Ibid., 504.

(13.) AFDD 1, Air Force Basic Doctrine, 18.

(14.) Lewis quotes Protocol I of the Geneva conventions, art. 57 (2) (c) (iii) in his article "Law of Aerial Bombardment," 487.

(15.) Ibid., 501.

(16.) Ibid., 493.

(17.) John S. Foster and Larry D. Welch, "The Evolving Battlefield," Physics Today 53, no. 12 (December 2000): 31,

(18.) Sakulich, Precision Engagement, 15.

(19.) Ibid., 14.

(20.) Thomas A. Keaney and Eliot A. Cohen, Gulf War Air Power Survey: Summary (Washington, DC: GPO, 1993), 543.

(21.) U.S. Air Force Transformation Flight Plan, 61.

(22.) Keaney and Cohen, Gulf War Air Power Survey, 530.

(23.) Chester W. Richards, A Swift, Elusive Sword: What If Sun Tzu and John Boyd Did a National Defense Review? 2d ed. (Washington, DC: Center for Defense Review, 2003), 51.

(24.) Sakulich, Precision Engagement, iv.

(25.) Joint Publication 3-60, Joint Doctrine for Targeting, 17 January 2002, I-4.

(26.) Ibid., I-1.

MAJ JACK SINE, USAF, I would like to acknowledge the contributions of all the members of AF/XORW, Air Staff Weapons Requirements, for their assistance in developing this definition. In particular, guidance and input from Mr. Dave Detore were invaluable in providing coherence to this definition in the context of the future of USAF weapons.
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