April 14, 2009

Technical and Legal Background on Cluster Munitions

Cluster munitions are large weapons containing dozens or hundreds of smaller submunitions. After being dropped from the air or fired from the ground, parent cluster munitions open in the air, releasing and dispersing their submunitions over a wide area. The submunitions from air-dropped cluster munitions (delivered by a variety of aircraft) are called bomblets, and those from ground-launched cluster munitions (delivered by artillery, mortar, rocket, and missile systems) are sometimes called grenades. Generally, both cluster munitions and their submunitions are unguided weapons.

Cluster munitions are notorious for the humanitarian harm they cause. They kill and injure civilians during attacks because of their broad area effect. They cause additional casualties after the fact because they leave large numbers of explosive duds. Human Rights Watch field researchers have documented civilian casualties from the weapon in Kosovo, Afghanistan, Iraq, Lebanon, and Israel.[1] In the August 2008 conflict in Georgia, both sides—Russia and Georgia—used cluster munitions. Again cluster munitions killed and injured civilians.

The use of cluster munitions often violates existing international humanitarian law. The laws of war prohibit means and methods of warfare that fail to distinguish between combatants and non-combatants, including using certain weapons in an inherently indiscriminate way. While not addressing use of cluster munitions, a CCW protocol lays out obligations designed to reduce the post-conflict danger of weapons. Strengthening and clarifying the law, the new Convention on Cluster Munitions goes further. It comprehensively bans cluster munitions and establishes remedial measures to alleviate the harm they cause to civilians. Although it has not yet entered into force, the treaty creates norms agreed to by 107 states at its adoption in May 2008. It was opened for signature on December 3, 2008, in Oslo and, as of March 2009, had been signed by 96 countries.

Cluster Munitions and their Humanitarian Effects

Cluster munitions are designed to blanket a wide area with explosive submunitions. The military values cluster munitions precisely because of this area effect. The weapons can destroy broad targets, including airfields and surface-to-air missile sites. They are also used against moving targets or those with imprecise locations, such as tanks and troops. Another benefit for the military is that many submunitions have multiple purposes; they are often both antipersonnel and anti-armor weapons.The military advantages of cluster munitions, however, must be weighed against harm to civilians and civilian property both during and after strikes.

The humanitarian effects of a cluster munition attack are often more serious than those of attacks using other types of weapons because of the wide dispersal of submunitions. Even if a cluster munition hits its target, which is not guaranteed because it is usually unguided, the submunitions may kill or injure civilians within the intended footprint. The inherent risks to civilian life and property increase when a military uses cluster munitions in or near populated areas, a common occurrence. If cluster munitions are used in an area where combatants and civilians commingle, civilian casualties are almost assured.

Cluster munitions also have problematic aftereffects because many submunitions do not explode upon impact as intended. All weapons have some rate of failure, but cluster munitions present greater danger due to the large number of submunitions released. In addition, certain design characteristics, based on cost and size considerations, increase the likelihood of submunition failure. Manufacturers and militaries have typically indicated that failure rates for submunitions under test conditions range between 5 and 20 percent; however, under real combat conditions, actual failure rates tend to be even higher. As a result every cluster munition strike leaves unexploded submunitions. The initial failure, or dud rate (that is the percentage of submunitions that do not explode), not only reduces the immediate military effectiveness of cluster munitions but also puts civilians at great risk. Given the highly unstable nature of unexploded submunitions, they may explode at the slightest touch or movement. Often hidden by foliage, mud, or other features of the environment, these submunitions become de facto landmines, killing or injuring civilians returning to the battle area after an attack. Duds cause socioeconomic harm as well as casualties because they prevent civilians from safely using their land and harvesting their crops.

Existing International Humanitarian Law

During the armed conflict between Russia and Georgia in August 2008, the military forces of both parties were bound under international humanitarian law to respect and protect civilians and other persons not or no longer directly taking part in hostilities. The law also restricted the means and methods of warfare to which they could resort. With regard to the protection of civilians in times of armed conflict, the most relevant international humanitarian law provisions are in the four Geneva Conventions of 1949 and their First Additional Protocol of 1977; Russia and Georgia are both party to these instruments.[2]

The Principle of Distinction

The principle of distinction is one of the keystones of the law regulating protection of civilians during hostilities. It requires parties to a conflict to distinguish at all times between combatants and civilians.[3] Parties may not attack civilians or civilian objects and may only direct attacks against military objectives.[4] Military objectives are members of the armed forces, other persons taking a direct part in hostilities, and “those objects which by their nature, location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage.”[5] The laws of war prohibit attacks “of a nature to strike military objectives and civilians or civilian objects without distinction.”[6]

Attacks that violate the principle of distinction are considered indiscriminate and unlawful. Indiscriminate attacks include those that “are not directed at a specific military objective,” those that “cannot be directed at a specific military objective,” and those that “employ a method or means of combat the effects of which cannot be limited.”[7] Bombardments that treat as a single military objective a number of clearly separated and distinct targets are indiscriminate as well.[8]

Proportionality is a related principle of international humanitarian law. Attacks that violate the principle of proportionality are indiscriminate because they are “expected to cause incidental loss of civilian life, injury to civilians [or] damage to civilian objectives…which would be excessive in relation to the concrete and direct military advantage anticipated” from that attack.[9]

Feasible Precautions

When conducting military operations, parties to a conflict must also take “constant care” to spare the civilian population and civilian objects from the effects of hostilities. For example, belligerents must take “all feasible precautions” to minimize harm to civilians when choosing their means and methods of warfare, and they must refrain from launching disproportionate attacks.[10] The enemy’s failure to respect one or more of these precautions does not permit the other party to the conflict to ignore precautions on its side.

International Humanitarian Law Applied to Cluster Munitions

Indiscriminate Use of Cluster Munitions

Cluster munitions raise serious concerns under numerous provisions of international humanitarian law. Cluster munition strikes in or near civilian population centers should be presumed indiscriminate because the weapons cannot be precisely targeted at specific military objectives and, in particular, the submunitions are almost always unguided. When cluster munitions are fired into civilian areas, civilian casualties and damage to civilian infrastructure are extremely difficult to avoid. They thus violate the rule that prohibits attacks that use a method of warfare that “cannot be directed at a specific military objective.”[11]

Whether a cluster strike is discriminate must be judged not only on its immediate impact but also on its aftereffects. Submunition duds do not distinguish between combatants and civilians and will likely injure or kill whoever disturbs them. The effects become more dangerous if the submunitions litter an area frequented by civilians or the dud rate is high (due to poor design, age, use in inappropriate environments, or delivery from inappropriate altitudes or distances). The large number of submunitions released by cluster munitions combined with a high dud rate makes the aftereffects in or near civilian areas particularly deadly. In that situation in particular, the unexploded duds raise concerns under the international humanitarian law provision that prohibits attacks that “employ a method or means of combat the effects of which cannot be limited.”[12]

Disproportionate Use of Cluster Munitions

The lawfulness of an attack may also be determined by its disproportionate effect on civilians. A cluster attack will be unlawfully disproportionate if expected civilian harm outweighs anticipated military advantage. Attacks in or near populated areas are particularly likely to be disproportionate given their predictable civilian casualties at the time of a strike.

Expected civilian harm encompasses casualties over time as well as immediate civilian losses.[13] It is increasingly accepted that long-term effects should be a factor in judging the proportionality of cluster munition attacks, and the long-term effects of cluster munitions are foreseeable.[14] The preamble of the final declaration of the Third Review Conference of States Parties to the CCW recognizes “the foreseeable effects of explosive remnants of war on civilian populations as a factor to be considered in applying the international humanitarian law rules on proportionality in attack and precautions in attack.”[15] States parties, including Georgia and Russia, adopted this language on November 17, 2006.

Taking into account both strike and post-strike civilian harm greatly increases the likelihood that the harm will be excessive in relation to the military advantage sought. It is especially true if an attack occurred in or near a populated area or in an area to which people might return. Based on its field research in Yugoslavia, Afghanistan, Iraq, and Lebanon, as well as Georgia, Human Rights Watch believes that when cluster munitions are used in any type of populated area, there should be a strong, if rebuttable, presumption that the attack is disproportionate.[16]

The Requirement to Take Precautions

States are legally bound to take “all feasible precautions” to minimize civilian harm. Given that cluster munition use in or near populated areas virtually guarantees civilian harm, it should be considered unlawful under this requirement.

Protocol V on Explosive Remnants of War

Protocol V on ERW, an instrument attached to the CCW, applies to cluster munitions. Its definition of ERW, which covers almost all conventional weapons, encompasses cluster munitions that did not explode on impact or were abandoned.[17] Russia submitted its consent to be bound by the protocol on July 21, 2008, and it entered into force for the state six months later, that is in January 2009. Georgia agreed to be bound on December 22, 2008. It will not enter into force for Georgia until June 2009, so the instrument does not yet bind the state. Nevertheless, Georgia may not “defeat the object and purpose of the treaty” in the interim.[18]

Protocol V lays out obligations for clearing ERW that are designed to reduce their humanitarian effects. Affected states parties must clear ERW in their territory and take steps to protect civilians, such as by instituting risk education programs.[19] States parties that are responsible for using weapons that leave ERW have specific obligations. Article 3 requires user states parties that are no longer in control of an affected area to “provide where feasible, inter alia technical, financial, material or human resources assistance” for clearance of ERW.[20] User states parties must also retain and make available any information, such as ERW types, numbers, and locations, that will facilitate clearance and risk education.[21]

While Protocol V is a relatively modest instrument[22] and does not prohibit or even restrict the use of cluster munitions, it does establish standards for reducing the harm of submunition duds to which Russia and Georgia, as states parties, should adhere.

The Convention on Cluster Munitions

While existing international humanitarian law prohibits the worst uses of cluster munitions, a new treaty, the Convention on Cluster Munitions, comprehensively bans the weapon. Both a disarmament and humanitarian treaty, it not only prohibits use, production, transfer, and stockpiling, but also establishes strong remedial measures to enhance protections for civilians. The Convention on Cluster Munitions has not yet entered into force, and neither Russia nor Georgia participated in its negotiation. Nevertheless, the convention reflects the strong opposition to cluster munitions within the international community.

In 2006 the failure of states to approve a negotiating mandate for a CCW cluster munition protocol, combined with Israel’s shocking use of cluster munitions in Lebanon, spurred a movement to create a treaty outside the CCW. The Oslo Process, named for the site of its first meeting, began in February 2007. On May 30, 2008, all 107 participating states at the final conference in Dublin adopted the text of the new Convention on Cluster Munitions.[23] The convention was opened for signature on December 3, 2008, and to date, 96 countries have signed and six have ratified. It will enter into force six months after the thirtieth instrument of ratification or accession, acceptance, or approval is deposited.[24]

Key Provisions of the Convention on Cluster Munitions

While all of its articles relate to cluster munitions, the Convention on Cluster Munitions encompasses a set of core obligations, outlined below, that are particularly relevant to the conflict between Georgia and Russia. They include both preventive and remedial measures. The former are designed to prevent the kind of use that occurred in Georgia. The latter seek to alleviate the humanitarian effects of use that has already taken place. Together they address the immediate as well as long-term effects of cluster munitions. The treaty does not allow reservations, which strengthens the power of its provisions.[25]

Under Article 1’s basic prohibitions on cluster munitions, states parties undertake “never under any circumstances” to use, produce, transfer, or stockpile cluster munitions, or to “assist, encourage or induce anyone to engage” in any of these prohibited activities.[26] In Article 3, the Convention on Cluster Munitions requires states parties to destroy their stockpiles of cluster munitions within eight years.[27] In Article 2(2), the convention defines a cluster munition as “a conventional munition that is designed to disperse or release explosive submunitions each weighing less than 20 kilograms, and includes those explosive submunitions.”[28]

States parties are also obligated to take remedial measures. Article 4 requires states parties to clear cluster munition remnants in areas under their “jurisdiction or control” within ten years and to provide for risk education.[29] It “strongly encourage[s]” states parties that used or abandoned cluster munitions prior to the convention’s entry into force to assist the affected state with clearance.[30] Article 5 lays out states parties’ obligations to assist victims, defined broadly to cover both individuals directly impacted by the weapons and their affected families and communities.[31]

Finally, Article 6 on international cooperation and assistance lays out obligations for states parties “in a position to do so” to provide assistance to affected states.[32]

The Importance of Joining the Convention on Cluster Munitions

States should sign and ratify the Convention on Cluster Munitions as soon as possible. Their support for the treaty will help prevent future use of cluster munitions like that which occurred in Georgia. By signing the treaty, a state undertakes to accept the principle of a comprehensive prohibition on cluster munitions because signatories cannot “defeat the object and purpose of the treaty.”[33] The more signatories there are, the more the weapon will be stigmatized. By ratifying the treaty, a state undertakes to be legally bound by its specific provisions. The sooner states ratify the instrument, the sooner it enters into force, and the more ratifications it garners, the greater its legal influence will be.

While the Convention on Cluster Munitions is awaiting enough ratifications to enter into force, it can still influence the behavior of states, even those not yet party to it, such as Russia and Georgia. Its already widely accepted standards have put states on notice that certain actions will draw condemnation from the international community. Stigmatization has led most states to follow the provisions of the Mine Ban Treaty, even if they are not party. In recent years, Burma is the only country to make significant use of antipersonnel mines.[34] The Convention on Cluster Munitions has the potential to have a similar impact.

Russia and Georgia, in particular, should sign and ratify, or at least follow the principles of, the Convention on Cluster Munitions as soon as they can. Many in the international community condemned their use of cluster munitions in Georgia.[35] Publicly supporting the convention would demonstrate that they are in step with widely accepted legal principles. Russia and Georgia could also mitigate the harm they caused in the 2008 conflict by meeting the convention’s obligations on clearance, risk education, and victim assistance. Finally, Georgia would benefit from joining the Convention on Cluster Munitions because it would be eligible to receive international assistance for addressing the aftereffects of cluster munitions.


[1] Human Rights Watch, Civilian Deaths in the NATO Air Campaign, vol. 12, no. 1(D), February 2000, http://www.hrw.org/en/node/78680/; Fatally Flawed: Cluster Bombs and Their Use by the United States in Afghanistan,vol. 14, no. 7(G), December 2002, http://www.hrw.org/en/reports/2002/12/18/fatally-flawed-0/; Off Target: The Conduct of the War and Civilian Casualties in Iraq (New York: Human Rights Watch, 2003), http://www.hrw.org/en/reports/2003/12/11/target-0/; Civilians under Assault: Hezbollah’s Rocket Attacks on Israel in the 2006 War, vol. 19, no. 3(E), August 2007, http://www.hrw.org/en/reports/2007/08/28/civilians-under-assault/, pp. 44-48; Flooding South Lebanon: Israel’s Use of Cluster Munitions in Lebanon in July and August 2006,vol.20, no. 2(E), February 2008, http://www.hrw.org/en/reports/2008/02/16/flooding-south-lebanon-0/.

[2] Geneva Convention for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field (First Geneva Convention), adopted August 12, 1949, 75 U.N.T.S. 31, entered into force October 21, 1950; Geneva Convention for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea (Second Geneva Convention), adopted August 12, 1949, 75 U.N.T.S. 85, entered into force October 21, 1950; Geneva Convention Relative to the Treatment of Prisoners of War (Third Geneva Convention), adopted August 12, 1949, 75 U.N.T.S. 135, entered into force October 21, 1950; Geneva Convention Relative to the Protection of Civilian Persons in Time of War (Fourth Geneva Convention), adopted August 12, 1949, 75 U.N.T.S. 287, entered into force October 21, 1950; Protocol Additional to the Geneva Conventions of 12 August 1949 relating to the Protection of Victims of International Armed Conflicts (Protocol I), adopted June 8, 1977, 1125 U.N.T.S. 3, entered into force December 7, 1978 (“Protocol I”).

[3] See Legality of the Threat of Use of Nuclear Weapons, Advisory Opinion, International Court of Justice, July 8, 1996, para. 78. “States must never make civilians the object of attack and must consequently never use weapons that are incapable of distinguishing between civilian and military targets.” The International Court of Justice interpreted the principle of distinction as falling within the remits of customary international law, and Judge Bedjaoui even considered it to be jus cogens while Judge Guillaume stated that it was absolute. See Declaration of Judge Bedjaoui, para. 21, and Separate Opinion of Judge Guillaume, para. 5.

[4] Protocol I, art. 48.

[5] Ibid., arts. 51(3), 52.

[6] Ibid., art. 51(4).

[7] Ibid., art. 51(4)(a, b, c).

[8] Ibid., art. 51(5)(a).

[9] Ibid., art. 51(5)(b).

[10] Ibid., art. 57.

[11] Ibid., art. 51(4)(b).

[12] Ibid., art. 51(4)(c).

[13] See generally Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, on the issue of proportionality and long-term impact of a weapon.

[14] For the foreseeability of the long-term impact of cluster munitions, see generally Human Rights Watch, Fatally Flawed; Off Target; Flooding South Lebanon.

[15]Third Review Conference of the High Contracting Parties to the CCW, “Final Document, Part II, Final Declaration,” CCW/CONF.III/11 (Part II), Geneva, November 7-17, 2006, p. 4

[16] Human Rights Watch and the International Human Rights Clinic, Harvard Law School, Cluster Munitions and the Proportionality Test:Memorandum to the Delegates of the Convention on Conventional Weapons, April 2008, http://www.hrw.org/sites/default/files/related_material/arms0408web.pdf.

[17] Protocol on Explosive Remnants of War to the Convention on Conventional Weapons (Protocol V), adopted November 27, 2003, U.N. Doc. CCW/MSP/2003/2, entered into force November 13, 2006, art. 2 (“Protocol V”).

[18] Vienna Convention on the Law of Treaties, adopted May 23, 1969, 1155 U.N.T.S. 331, entered into force January 27, 1980, art. 18.

[19] Protocol V, arts. 3, 5. Other articles elaborate on provisions related to ERW clearance.

[20] Ibid., art. 3.

[21] Ibid., art. 4.

[22] Many of Protocol V’s provisions have qualifying language. For example, Article 3 says “as soon as feasible,” Article 4 “as far as practicable,” and Articles 7 and 8 “in a position to do so.” Its “generic preventive measures,” laid out in Article 9 and the Technical Annex, are voluntary and refer to measures for reducing a weapon’s failure rate, not eliminating or circumscribing its use.

[23] Convention on Cluster Munitions, adopted May 30, 2008, Diplomatic Conference for the Adoption of a Convention on Cluster Munitions, CCM/77, opened for signature December 3, 2008, http://www.clustermunitionsdublin.ie/pdf/ENGLISHfinaltext.pdf (accessed March 30, 2009) (“Convention on Cluster Munitions”).

[24] Ibid., art. 17.

[25] Ibid., art. 19.       

[26] Ibid., art. 1(1). By using the term “anyone,” the absolute prohibition applies to non-state actors as well as states.

[27] Ibid., art. 3(2). In exceptional circumstances, four-year extensions can be granted.

[28] Ibid., art. 2(2). The Convention on Cluster Munitions definition explicitly excludes some weapons that meet that technical description but do not cause the same humanitarian harm as cluster munitions, but none of the weapons used in Georgia fall under the exclusion.

[29] Ibid., art. 4(1). The Convention on Cluster Munitions allows for five-year extensions for clearance for exceptional circumstances.

[30] Ibid., art. 4(4). That assistance can take a variety of forms, including “technical, financial, material or human,” but must include information on the types, quantities, and locations of cluster munitions used.

[31] Ibid., arts. 2(1), 5. In keeping with international humanitarian and human rights law, states parties must provide varied kinds of assistance, including medical care, rehabilitation, and psychological support, and “provide for…social and economic inclusion.”

[32] Ibid., art. 6.

[33] Vienna Convention on the Law of Treaties, art. 18.

[34] International Campaign to Ban Landmines, Landmine Monitor Report 2008: Toward a Mine-Free World (Ottawa: Mines Action Canada, 2008), p. 4. A number of rebel groups also continue to use antipersonnel mines, most notably in Colombia and Burma. Ibid., pp. 5-6.

[35]For governmental or intergovernmental condemnation, see, for example, “Statement by Minister for Foreign Affairs on Alleged Use of Cluster Bombs in Georgia,” Irish Department of Foreign Affairs press release, August 21, 2008, http://www.foreignaffairs.gov.ie/home/index.aspx?id=72512 (accessed January 28, 2009); “Norway Deeply Deplores Any Use of Cluster Munitions in the Georgia Conflict,” Permanent Mission of Norway to the UN news release, September 2, 2008, http://www.norway-un.org/Selected+Topics/Disarmament/020908_Georgia_Clustermunition.htm (accessed January 28, 2009); “Statement by the Permanent Representative of the Kingdom of the Netherlands to the OSCE regarding the Death of Dutch Cameraman Stan Storimans on 12 August 2008,” PC.DEL/869/08, October 23, 2008, http://www.osce.org/documents/pc/2008/10/34651_en.pdf (accessed January 28, 2009); “Rice Says Russia Becoming an Outlaw in Georgia,” Reuters, August 19, 2008, http://www.reuters.com/article/GCA-Georgia/idUSN1933114120080820 (accessed January 28, 2009); “Human Rights and Humanitarian Principles Have Been Seriously Violated in the South Ossetia Conflict, Reports Thomas Hammarberg after an Eight-Day Mission,” Council of Europe press release, 612(2008), September 5, 2008, https://wcd.coe.int/ViewDoc.jsp?id=1337409&Site=DC (accessed November 16, 2008); “EU Calls on Russia, Georgia to Clear Cluster Bombs: France,” September 2, 2008, Agence France Presse, September 2, 2008, http://www.eubusiness.com/news-eu/1220365022.62/ (accessed November 16, 2008). Many nongovernmental organizations (NGOs), including Human Rights Watch, also condemned the use of cluster munitions by both sides. “CMC Condemns Georgian Use of Cluster Bombs,” Cluster Munition Coalition press release, September 2, 2008, http://stopclustermunitions.org/news/?id=667 (accessed January 28, 2009); “Survivor Corps Criticizes Use of Cluster Munitions in Russia Georgia Conflict,” Survivor Corps news release, September 1, 2008, http://banclusterbombs.smnr.us/ (accessed January 28, 2009); “Handicap International Condemns the Use of Cluster Bombs,” Handicap International news release, August 19, 2008, http://www.handicap-international.fr/en/our-fight-against-landmines-an/en-bref/handicap-international-condemns-the-use-of-cluster-bombs/index.html?cHash=c901adf78d (accessed January 28, 2009); “Georgia: UK Must Condemn Russian Use of Cluster Bombs,” Landmine Action press release, August 15, 2008, http://www.landmineaction.org/resources/resource.asp?resID=1104&PLID=1012&pageID= (accessed January 28, 2009).