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
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
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
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
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
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.
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
(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, http://www.af.mil/library/posture/
(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
(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.
maxwell.af.mil/airchronicles/apj/apj01/fal01/vorfal01. html (accessed 19
(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,"
(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.