Cluster munitions can be fired by rockets, mortars, and artillery, or dropped by aircraft. They explode in the air, sending dozens, even hundreds, of submunitions or explosive bomblets over a wide area. Their dispersal over a wide area effect virtually guarantees civilian casualties when they are used in populated areas, while submunitions often fail to explode on initial impact, leaving dangerous explosive remnants that act like landmines and explode when handled.

Unexploded submunitions typically contain more explosives than antipersonnel mines, which makes them more lethal. Survivors often suffer the amputation of more than one limb as well as burns, shrapnel injuries, and damage to eyesight and hearing.

Cluster munitions have been used by at least 19 countries since World War II, particularly by Israel, Russia, and the United States. The Syrian government’s use of cluster munitions since 2012 has caused numerous civilian casualties. Other nations that are contaminated by cluster munition remnants include Cambodia, Lao PDR, Vietnam as well as Afghanistan, Iraq, and Serbia.

Israel's massive use of the weapon in Lebanon in August 2006 resulted in more than 200 civilian casualties in the year following the ceasefire and helped serve as a catalyst that propelled governments to adopt a legally-binding international instrument in May 2008 prohibiting cluster munitions.  To date, a total of 113 nations are party to the Convention on Cluster Munitions, which comprehensively bans the use, production, transfer, and stockpiling of cluster munitions and requires clearance of contaminated areas as well as assistance to victims.

The Cluster Munition Coalition (CMC) is a worldwide coalition of non-governmental organizations launched in 2003 to address the unacceptable harm that cluster munitions were inflicting on civilian populations. The CMC’s Cluster Munition Monitor initiative systematically monitors and document nations' compliance with the Convention on Cluster Munitions. According to Cluster Munition Monitor, since the convention became binding international law on August 1, 2010, more than one million cluster munitions and 122 million submunitions have been destroyed from stockpiles.

United States

While the historical record is incomplete, the US has produced cluster munitions and in the past transferred hundreds of thousands of cluster munitions, containing tens of millions of submunitions, to at least 30 countries. The US has used cluster munitions in a number of countries including Afghanistan, Cambodia, Iraq, Lao PDR, Serbia, and Vietnam. The last US use of cluster munitions was believed to be in December 2009 in Yemen.

The US did not directly participate, not even as an observer, in the diplomatic Oslo Process in 2007 and 2008 that resulted in the Convention on Cluster Munitions. However, US Department of State cables made public by Wikileaks from late 2010 through 2011 show how the US attempted to influence its allies, partners, and other states during the Oslo Process to affect the outcome of the negotiations, especially with respect to the issue of “interoperability” (joint military operations between the US and States Parties to the convention).

While the US has acknowledged the “important contributions” of the Convention on Cluster Munitions, it led an unsuccessful effort to create an alternate international law to regulate and not ban cluster munitions through the Convention on Conventional Weapons (CCW), to which it is party. The US said it was “deeply disappointed” at the CCW’s failure in November 2011 to conclude the draft protocol, in effect ending CCW work on this matter and leaving the Convention on Cluster Munitions as the only international law to specifically address these weapons.

The Obama administration has continued to implement a cluster munition policy created under President George W. Bush in July 2008. Under the 2008 Department of Defense (DoD) policy, by the end of 2018 the US will no longer use cluster munitions that result in more than one percent unexploded ordnance (UXO). Under the policy, all cluster munition stocks “that exceed operational planning requirements or for which there are no operational planning requirements” must be removed from active inventories and demilitarized as soon as practicable. 

While the US is not a party to the Convention on Cluster Munitions, it has on occasion criticized the use of these weapons. In May 2013, the US voted in in favor of a UN General Assembly resolution that strongly condemned Syrian government use of cluster munitions.” In April 2011, then-Secretary of State Hillary Clinton condemned the use of cluster munitions by Libyan government forces.

In a 17 July 2013 letter to President Obama, senior US Senators Dianne Feinstein (D-CA) and Patrick Leahy (D-VT) described the US government’s cluster munitions policy as “outdated” and urged that it be “immediately” and “expeditiously” reviewed to put the US “on a path to join the international Convention on Cluster Munitions.” Senators Feinstein and Leahy have introduced the Cluster Munitions Civilian Protection Act to limit the use of cluster munitions to munitions that have a 99% or higher reliability rate, prohibit use of cluster munitions in areas where civilians are known to be present, and require a clearance plan if the US uses cluster munitions.