ȱ
•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ
˜›ȱ˜—›Žœœȱ
—›Ž ȱŽ’Œ”Ž›ȱ
™ŽŒ’Š•’œȱ’—ȱ’•’Š›¢ȱ ›˜ž—ȱ˜›ŒŽœȱ
Š—žŠ›¢ȱŘŞǰȱŘŖŖşȱ
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
ŝȬśŝŖŖȱ
   ǯŒ›œǯ˜Ÿȱ
ŘŘşŖŝȱ
ȱŽ™˜›ȱ˜›ȱ˜—›Žœœ
Pr
epared for Members and Committees of Congress

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
ž––Š›¢ȱ
Cluster munitions are air-dropped or ground-launched munitions that release a number of smaller
submunitions intended to kill enemy personnel or destroy vehicles. Cluster munitions were
developed in World War II and are part of many nations’ weapons stockpiles. Cluster munitions
have been used frequently in combat, including the early phases of the current conflicts in Iraq
and Afghanistan. Cluster munitions have been highly criticized internationally for causing a
significant number of civilian deaths, and efforts have been undertaken to ban and regulate their
use. The Department of Defense (DOD) continues to view cluster munitions as a military
necessity but has instituted a policy to reduce the failure rate of cluster munitions to 1% or less by
2018. This report will be updated.


˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
˜—Ž—œȱ
What Are Cluster Munitions?.......................................................................................................... 1
History ............................................................................................................................................. 1
Cluster Munitions Criticisms........................................................................................................... 2
Failure Rate ............................................................................................................................... 2
Lack of Self-Destruct Capability............................................................................................... 2
International Attempts to Regulate Use........................................................................................... 3
UN Convention on Prohibitions or Restrictions on the Use of Certain Conventional
Weapons (CCW) .................................................................................................................... 3
CCW Fails to Agree on a Cluster Munitions Pact..................................................................... 3
Oslo Convention on Cluster Munitions..................................................................................... 4
Current U.S. Policy on Cluster Munitions....................................................................................... 4
Department of Defense (DOD) Policy on Cluster Munitions ........................................................ 5
DOD Efforts to Reduce Unexploded Ordnance Rates for Its Cluster Munitions............................ 5
Potential Issues for Congress........................................................................................................... 6
Cluster Munitions in an Era of Precision Weapons................................................................... 6
Weapons in Lieu of Cluster Munitions...................................................................................... 6
Is the CCW a Viable Forum for Regulating Cluster Munitions? .............................................. 6

˜—ŠŒœȱ
Author Contact Information ............................................................................................................ 7

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
‘Šȱ›Žȱ•žœŽ›ȱž—’’˜—œǵŗȱ
Cluster munitions are weapons that open in mid-air and dispense smaller submunitions—
anywhere from a few dozen to hundreds—into an area. They can be delivered by aircraft or from
ground systems such as artillery, rockets, and missiles. Cluster munitions are valued militarily
because one munition can kill or destroy many targets within its impact area, and fewer weapons
systems are needed to deliver fewer munitions to attack multiple targets. Cluster munitions also
permit a smaller force to engage a larger adversary and are considered by some an “economy of
force” weapon. Many cluster munitions rely on simple mechanical fuzes that arm the submunition
based on its rate of spin and explode on impact or after a time delay. A newer generation of
sensor-fuzed submunitions are being introduced by a number of nations to improve the munitions’
and submunitions’ accuracy and to reduce the large number of residual unexploded submunitions.
These sensor-fuzed submunitions are designed to sense and destroy vehicles without creating an
extensive hazard area of unexploded submunitions.
’œ˜›¢Řȱ
Cluster bombs were first used in World War II, and inclusive of their debut, cluster munitions
have been used in at least 21 states by at least 13 different countries. Cluster munitions were used
extensively in Southeast Asia by the United States in the 1960s and 1970s, and the International
Committee of the Red Cross (ICRC) estimates that in Laos alone, 9 to 27 million unexploded
submunitions remained after the conflict resulting in over 10,000 civilian casualties to date.
Cluster munitions were used by the Soviets in Afghanistan, by the British in the Falklands, by the
Coalition in the Gulf War, and by the warring factions in Yugoslavia. In Kosovo and Yugoslavia
in 1999, NATO forces dropped 1,765 cluster bombs containing approximately 295,000
submunitions. From 2001-2002, the United States dropped 1,228 cluster bombs containing
248,056 submunitions in Afghanistan, and U.S. and British forces used almost 13,000 cluster
munitions containing an estimated 1.8 to 2 million submunitions during the first three weeks of
combat in Iraq in 2003. Senior U.S. government officials have stated that the United States has
not used cluster munitions since 2003, during the intervention in Iraq.3 It is widely believed that
confusion over U.S. cluster submunitions (BLU-97/B) that were the same color and size as air-
dropped humanitarian food packets played a major role in the U.S. decision to suspend cluster
munitions use in Afghanistan but not before using them in Iraq.
In 2006, Israeli use of cluster munitions against Hezbollah forces in Lebanon resulted in
widespread international criticism. Israel was said to have fired significant quantities of cluster
munitions—primarily during the last three days of the 34-day war after a UN cease fire deal had
been agreed to4—resulting in almost 1 million unexploded cluster bomblets to which the UN

1 Information in this section unless otherwise noted is from Mark Hiznay, “Operational and Technical Aspects of
Cluster Munitions,” United Nations Institute for Disarmament Research Disarmament Forum,” 2006, pp. 15-25.
2 Ibid.
3 Stephen D. Mull, Acting Assistant Secretary of State for Political-Military Affairs, U.S. Cluster Munitions Policy,
On-the-Record Briefing, Washington, D.C, May 21, 2008.
4 Scott Peterson, “Cluster Bombs: A War’s Perilous Aftermath,” Christian Science Monitor, February 7, 2007 and
“Israel Criticized for Cluster Bombs,” Los Angeles Times, February 1, 2008.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
ŗȱ

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
attributed 14 deaths during the conflict.5 Reports maintain that Hezbollah fired about 113 “cluster
rockets” at northern Israel and, in turn, Israel’s use of cluster munitions supposedly affected 26%
of southern Lebanon’s arable land and contaminated about 13 square miles with unexploded
submunitions.6 One report states that there was a failure rate of upwards of 70% of Israel’s cluster
weapons.7
•žœŽ›ȱž—’’˜—œȱ›’’Œ’œ–œȱ
The fundamental criticisms of cluster munitions are that they disperse large numbers of
submunitions imprecisely over an extended area, that they frequently fail to detonate and are
difficult to detect, and that submunitions can remain explosive hazards for decades. Civilian
casualties are primarily caused by munitions being fired into areas where soldiers and civilians
are intermixed, inaccurate cluster munitions landing in populated areas, or civilians traversing
areas where cluster munitions have been employed but failed to explode. Two technical
characteristics of submunitions—failure rate and lack of a self-destruct capability—have received
a great deal of attention.
Š’•ž›ŽȱŠŽŞȱ
There appears to be significant discrepancies among failure rate estimates. Some manufacturers
claim a submunition failure rate of 2% to 5%, whereas mine clearance specialists have frequently
reported failure rates of 10% to 30%. A number of factors influence submunition reliability. These
include delivery technique, age of the submunition, air temperature, landing in soft or muddy
ground, getting caught in trees and vegetation, and submunitions being damaged after dispersal,
or landing in such a manner that their impact fuzes fail to initiate.
ŠŒ”ȱ˜ȱŽ•ȬŽœ›žŒȱŠ™Š‹’•’¢ȱ
Submunitions lacking a self-destruct capability—referred to as “dumb” munitions—are of
particular concern because they can remain a hazard for decades, thereby increasing the potential
for civilian casualties. Some nations are developing “smart” or sensor-fuzed weapons with greater
reliability and a variety of self-destruct mechanisms intended to address the residual hazard of
submuntions.9 Experts maintain that self-destruct features reduce—but do not eliminate—the
unexploded ordnance problem caused by cluster munitions and that the advantage gained by
using “smart” cluster munitions are negated when high-failure rate and/or “dumb” cluster
munitions are used in the same area.10 For some nations, replacing “dumb” and high-failure rate

5 “Major Violations on Both Sides in Israel-Lebanon Conflict, Say UN Experts,” United Nations Office at Geneva
News & Media, October 4, 2006.
6 Scott Peterson.
7 Ibid. Failure rate as described here is either a failure to detonate on impact or a failure to detonate after a
predetermined time delay.
8 Unless otherwise noted, information in this section is from Mark Hiznay. p. 22.
9 Gayle S. Putrich, “Cluster-Bomb Ban Exempts Some Smart Munitions,” Defense News, June 2, 2008, p. 4.
10 Hiznay, p. 23.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
Řȱ

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
cluster munitions may not be an option—China, Russia, and the Republic of Korea maintain that
they cannot afford to replace all current submunitions with “smart” submunitions.11
—Ž›—Š’˜—Š•ȱŽ–™œȱ˜ȱŽž•ŠŽȱœŽȱ
The use of cluster munitions is currently not prohibited under international law or governed by
international treaty. There are however, two major ongoing international initiatives to regulate
cluster munitions.
ȱ˜—ŸŽ—’˜—ȱ˜—ȱ›˜‘’‹’’˜—œȱ˜›ȱŽœ›’Œ’˜—œȱ˜—ȱ‘ŽȱœŽȱ˜ȱ
Ž›Š’—ȱ˜—ŸŽ—’˜—Š•ȱŽŠ™˜—œȱǻǼȱ
In an effort to restrict or ban specific types of weapons used in armed conflicts, 51 states
negotiated the CCW in 1980.12 When the treaty entered into force in December 1983, it applied
only to incendiary weapons, mines and booby-traps, and weapons intended to cause casualties
through very small fragments. Since then, some states parties have added provisions through
additional protocols to address other types of weapons. Negotiations on cluster munitions are
carried out under Protocol V on Explosive Remnants of War. The United States was originally
against any CCW negotiations on cluster munitions, but dropped its opposition in June 2007.
Some have characterized the CCW as “slow-moving,” “ponderous,” and “lacking life.”13
ȱŠ’•œȱ˜ȱ›ŽŽȱ˜—ȱŠȱ•žœŽ›ȱž—’’˜—œȱŠŒŗŚȱ
The delegates to the CCW failed to reach an agreement on a new protocol to specifically address
cluster munitions during their November 2008 meeting, although delegates stated their
commitment to continue work in 2009. Countries (including the United States) that posses most
of the world’s cluster munitions have stated their preference for the CCW as the proper forum
with dealing with cluster munitions. Russia and the United States had supposedly agreed to the
proposed protocol, which would have required both countries to “significantly overhaul their
existing [cluster munitions] stocks,” but some countries supporting the Oslo Convention on
Cluster Munitions rejected the proposed text. Although delegations have agreed to meet again in
February and April 2009 to continue negotiations, there is increasing skepticism that further CCW
cluster munitions negotiations will be of little value because many CCW nations have instead
opted to support the Oslo Convention.

11 Ibid.
12 Information in this section is from an Arms Control Association Fact Sheet. “Convention on Certain Conventional
Weapons Convention (CCW) at a Glance,” Washington, D.C., October 2007.
13 “A Change of Heart, or of Tactic?, Cluster Munitions,” The Economist, June 23, 2007.
14 Information in this section is from Jeff Abramson, “CCW Fails to Reach Cluster Munitions Pact,” Arms Control
Today,
December 2008, pp. 48-49.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
řȱ

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
œ•˜ȱ˜—ŸŽ—’˜—ȱ˜—ȱ•žœŽ›ȱž—’’˜—œȱ
15 Described as “frustrated with the CCW process,” in 2007 a number of CCW members—led by
Norway—initiated negotiations outside of the CCW to ban cluster munitions.16 On May 30, 2008,
they reached an agreement to ban cluster munitions.17 The United States, Russia, China, Israel,
Egypt, India, and Pakistan did not participate in the talks or sign the agreement. During the
Signing Conference in Oslo from December 3-4, 2008, 94 states signed the convention and four
of the signatories ratified the convention at the same time.18 China, Russia, and the United States
abstained, but France, Germany, and the United Kingdom were among the 18 NATO members to
sign the convention.19 The convention will enter into force six months after the 30th ratification is
deposited. The Oslo Convention on Cluster Munitions, inter alia, bans the use of cluster
munitions, as well as their development, production, acquisition, transfer, and stockpiling.20 The
Oslo Convention does not prohibit cluster munitions that can detect and engage a single target or
explosive submunitions equipped with an electronic self-destruction or self-deactivating
feature21—an exemption that seemingly permits sensor-fuzed or “smart” cluster submunitions.
ž››Ž—ȱǯǯȱ˜•’Œ¢ȱ˜—ȱ•žœŽ›ȱž—’’˜—œȱ
U.S. government officials have stated that “the United States relies on them [cluster munitions] as
an important part of our own defense strategy,” and that Washington’s preferred alternative to a
ban would be “to pursue technological fixes that will make sure that these weapons are no longer
viable once the conflict is over.”22 The United States has also agreed to address the humanitarian
aspects of cluster munitions use through the Convention on Certain Chemical Weapons (CCW)
rather than the Oslo Convention on Cluster Munitions.23 U.S. officials note that:
Cluster munitions are available for use by every combat aircraft in the U.S. inventory, they
are integral to every Army or Marine maneuver element and in some cases constitute up to
50 percent of tactical indirect fire support. U.S. forces simply can not fight by design or by
doctrine without holding out at least the possibility of using cluster munitions.24

15 For detailed information on the Convention on Cluster Munitions, see http://www.clustermunitionsdublin.ie/
documents.asp.
16 Arms Control Association Fact Sheet. “Convention on Certain Conventional Weapons Convention (CCW) at a
Glance,” Washington, D.C., October 2007.
17 Kevin Sullivan and Josh White, “111 Nations, Minus the U.S., Agree to Cluster-Bomb Ban,” Washington Post, May
29, 2008.
18 Convention on Cluster Munitions Homepage http://www.clusterconvention.org/ accessed January 28, 2009.
19 Marina Malenic, “Dozens of Nations Sign Cluster Bomb Treaty, U.S. Begins Upgrading Related Technology,”
Defense Daily, December 5, 2008.
20 Diplomatic Conference for the Adoption of a Convention on Cluster Munitions, Convention on Cluster Munitions,
Dublin, Ireland, May 30, 2008 http://www.clustermunitionsdublin.ie/documents.asp.
21 Ibid.
22 Mull.
23 Unless otherwise noted information in this section is from Richard Kidd, Director of the Office of Weapons Removal
and Abatement, U.S. Department of State, “Is There a Strategy for Responsible U.S. Engagement on Cluster Munitions
?” April 28, 2008.
24 Ibid.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
Śȱ

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
The United States also maintains that using cluster munitions reduces the number of aircraft and
artillery systems needed to support military operations, and that if cluster munitions were
eliminated, significantly more money would need to be spent on new weapons systems,
ammunition, and logistical resources. Officials further suggest that if cluster munitions were
eliminated, most militaries would increase their use of massed artillery and rocket barrages,
which would likely increase destruction of key infrastructure. U.S. officials were concerned that
early versions of the Oslo Convention on Cluster Munitions would prevent military forces from
non-states parties from providing humanitarian and peacekeeping support and significantly affect
NATO military operations, but the version signed May 30, 2008, does permit States Parties to
engage in military cooperation and operations with non-States Parties (Article 21, Paragraph 3).
Ž™Š›–Ž—ȱ˜ȱŽŽ—œŽȱǻǼȱ˜•’Œ¢ȱ˜—ȱ•žœŽ›ȱ
ž—’’˜—œȱŘśȱ
On June 19, 2008, DOD issued its policy on cluster munitions, which recognizes the need to
minimize harm to civilians and infrastructure but also reaffirms the contention that “cluster
munitions are legitimate weapons with clear military utility.” The central directive in the
Pentagon’s new policy is the unwaiverable requirement that cluster munitions used after 2018
must leave less than 1% of unexploded submunitions on the battlefield. Prior to 2018, U.S. use of
cluster munitions with a greater than 1% unexploded ordnance rate must be approved by
Combatant Commanders. This policy will permit the development of a new generation of cluster
munitions less dangerous to civilians. While such a high level of performance might be
achievable under controlled laboratory conditions, previously mentioned factors such as delivery
technique, landing in soft or muddy ground, getting caught in trees and vegetation, and
submunitions being damaged after dispersal or landing could result in an appreciable number of
dud submunitions, even if it has a self-deactivation feature.
ȱ˜›œȱ˜ȱŽžŒŽȱ—Ž¡™•˜Žȱ›—Š—ŒŽȱŠŽœȱ
˜›ȱ œȱ•žœŽ›ȱž—’’˜—œȱ
DOD and the Services have been and are currently involved in efforts to reduce cluster munitions
failure rates. The Army’s Alternative Warhead Program (AWP) is intended to assess and
recommend new technologies to reduce or eliminate cluster munitions failure rates.26 The AWP
program is viewed as particularly relevant as the Pentagon estimates that “upward of 80 percent
of U.S. cluster munitions reside in the Army artillery stockpile.”27 In December 2008, the Army
decided to cease procurement of a Guided Multiple Launch Rocket System (GMLRS) warhead—
the Dual-Purpose Improved Conventional Munition (DPICM) warhead—because its
submunitions had a dud rate up to 5%.28 The Air Force is also acquiring cluster munitions that

25 Information in this section is from DOD Policy on Cluster Munitions and Unintended Harm to Civilians, June 19,
2008.
26 Daniel Wasserbly, “Army Warhead Program to Reduce Dud Rate for Cluster Munitions,” InsideDefense.com, July
21, 2008.
27 Ibid.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
śȱ

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
comply with the less than 1% failure rate—the CBU-97 Sensor Fuzed Weapon (SFW) and the
CBU-105 WCMD/SFW.29
˜Ž—’Š•ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
•žœŽ›ȱž—’’˜—œȱ’—ȱŠ—ȱ›Šȱ˜ȱ›ŽŒ’œ’˜—ȱŽŠ™˜—œȱ
It may be argued that even with advances in “sensor-fuzed” type submunitions that seek out and
destroy certain targets, cluster munitions are still essentially an indiscriminate area weapon in an
era where precision weapons are increasingly becoming the military norm. In Operation Desert
Storm in 1991, only about 10% of ordnance used were precision-guided, but by the time of the
Iraq invasion in 2003, “the ratio of ‘smart’ to dumb weapons was nearly reversed.”30 Since then,
this trend towards greater precision has continued, if not accelerated with the development of
precision rocket, artillery, mortar munitions, and smaller-precision aerial bombs designed to
reduce collateral damage.31 Given current and predicted future precision weaponry trends, cluster
munitions might be losing their military relevance—much as chemical weapons did between
World War I and World War II.
ŽŠ™˜—œȱ’—ȱ’Žžȱ˜ȱ•žœŽ›ȱž—’’˜—œȱ
According to the State Department, the U.S. military suspended its use of cluster munitions in
Iraq and Afghanistan in 2003. For subsequent military operations, where cluster munitions would
otherwise have been the weapon of choice, Congress might review what types of weapons were
substituted in place of cluster munitions and how effective they were in achieving the desired
tactical results. Also worth considering are effects-based weapons systems and operations, which
can achieve the same or similar effect against a potential target without applying a “kinetic
solution” such as a cluster munition. Such insights could prove valuable in analyzing U.S. policy
options on the future of cluster munitions.
œȱ‘ŽȱȱŠȱ’Š‹•Žȱ˜›ž–ȱ˜›ȱŽž•Š’—ȱ•žœŽ›ȱž—’’˜—œǵȱ
Given the failure of CCW delegates to reach an agreed protocol in November 2008 and the
signature of the Oslo Convention by prominent U.S. NATO allies, Great Britain, France, and
Germany, it has been suggested by some that it might be worth reevaluating the CCW as a means
to regulate cluster munitions. There are doubts that CCW efforts to develop a cluster munitions
protocol will be viable, as some nations that are part of the CCW who have also signed the Oslo

(...continued)
28 Kate Brannen, “Army Will Stop Procurement of GMLRS-DPICM After Final Deliveries,” InsideDefense.com,
December 1, 2008.
29
Marina Malenic, “Dozens of Nations Sign Cluster Bomb Treaty, U.S. Begins Upgrading Related Technology,” Defense
Daily,
December 5, 2008.
30 J.R. Wilson, “Pinpoint Accuracy: Bombs, Rockets, and Mortars Get New Brains,” Armed Forces Journal, January
2005, pp. 32-34.
31 Jeffrey Kofman, “Introducing the Small Diameter Bomb,” ABC News, February 16, 2008.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
Ŝȱ

•žœŽ›ȱž—’’˜—œDZȱŠŒ”›˜ž—ȱŠ—ȱ œœžŽœȱ˜›ȱ˜—›Žœœȱ
ȱ
Convention stand in opposition of a CCW protocol on cluster munitions. If the United States were
to become an active participant in the Oslo Convention, along with allies such as Great Britain,
France, and Germany, it might have a greater role in shaping the future of this convention. One
potential drawback should the United States support the Oslo Convention is that it could be seen
as undermining the entire CCW, which encompasses more than just cluster munitions. Such a
policy shift to support the Oslo convention could also have a detrimental impact on any future
CCW initiatives dealing with other conventional weapons.

ž‘˜›ȱ˜—ŠŒȱ —˜›–Š’˜—ȱ

Andrew Feickert

Specialist in Military Ground Forces
afeickert@crs.loc.gov, 7-7673




˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
ŝȱ