What Are Cluster Munitions?

Cluster munitions are weapons that release multiple submunitions (bomblets) over an area. They come in aerial bomb, artillery shell, and rocket forms. DPICM (Dual-Purpose Improved Conventional Munition) is the US Army's primary artillery-delivered cluster munition — a 155mm shell that releases 88 M42/M46 submunitions over approximately a football-field-sized area. Each submunition has a shaped-charge antitank capability and a fragmentation anti-personnel effect.

The military utility of cluster munitions lies in area coverage: a single DPICM shell can suppress and kill personnel across an area that would require multiple standard shells, making each gun-tube more effective at neutralizing infantry in the open, trench networks, and light vehicle concentrations.

The humanitarian concern is the "dud rate" — the percentage of submunitions that fail to detonate on impact and remain as unexploded ordnance (UXO) in soil and vegetation, posing post-conflict civilian casualty risks for years or decades. DPICM's nominal dud rates are 2–14% depending on variant and conditions — meaning per shell of 88 submunitions, 2–12 duds may remain on the ground.

The Artillery Shell Shortage: Why Ukraine Needed DPICM

By mid-2023, Ukraine's artillery situation had reached critical levels. Russia was firing an estimated 20,000–40,000 artillery rounds per day in peak fighting, against Ukraine's 4,000–7,000 per day. This 5:1 to 10:1 imbalance in artillery tube ammunition was the single greatest operational constraint on Ukrainian defensive and offensive operations — outstripping Russian advances in many sectors through sheer weight of fire.

Western 155mm shells were being consumed faster than Ukraine's allies could produce them. Production had only begun scaling up after decades of post-Cold War drawdown. The US held large legacy stocks of DPICM — 3 million+ rounds in the Army's reserve — that were not meeting current doctrine requirements and were slated for demilitarization. These rounds, already paid for and stored, represented a way to immediately address Ukraine's ammunition shortfall without delaying production of new shells.

The Biden administration approved DPICM transfer over the objections of some NATO allies and human rights organizations in July 2023. National Security Advisor Jake Sullivan stated that the decision was taken to help Ukraine defend itself in a critical period, and that Russia was already using cluster munitions extensively in Ukraine — making the humanitarian asymmetry argument against the transfer harder to sustain.

The Transfer: How Many and Which Variants

The initial transfer announced in July 2023 included an estimated 700,000–1 million DPICM rounds from US Army stocks. The specific variants transferred included M483A1 (88 submunitions, older, higher dud rates ~14%) and M864 (72 submunitions, range-extended base-bleed, dud rates reportedly ~6%). The US also provided documentation on U.S. intent to support post-war UXO clearance and indicated transfer only on Ukrainian commitments not to use cluster munitions in civilian areas.

Subsequent packages included additional DPICM rounds, and the US indicated the transfers addressed approximately 20–30% of Ukraine's total artillery shell consumption — a meaningful but not decisive supplement to conventional 155mm shell supply.

Battlefield Use and Effectiveness

Ukraine deployed DPICM primarily against Russian infantry concentrations in Donetsk, the Robotyne area in Zaporizhzhia, and defensive fighting in Avdiivka. Ukrainian artillery commanders consistently reported high effectiveness against Russian troops in trench systems and staging areas — particularly when Russian forces massed for assault operations at relatively predictable locations.

The area-effect characteristic was specifically valuable for suppressing areas too large to cover with pinpoint shells: Russian assault groups approaching with multiple squads across a 200m front could be simultaneously suppressed by a single DPICM round whereas the same effect would require 4–6 standard high-explosive rounds. Given Ukraine's ammunition scarcity, this multiplication of effect per shell was operationally significant.

Independent analysts assessing Ukrainian DPICM use reported it was relatively disciplined — primarily concentrated on confirmed military positions rather than civilian areas. Ukraine had strong incentives for such discipline because Ukrainian territory was involved: contaminating its own land with unexploded ordnance would directly harm Ukrainian civilians after liberation.

Russia's Cluster Munition Use: The Asymmetry

Russian forces have used cluster munitions throughout the war in Ukraine extensively and without restriction — including against Ukrainian civilian areas such as residential neighborhoods in Kharkiv, Mykolaiv, Zaporizhzhia, and other cities. Human Rights Watch and Amnesty International documented hundreds of instances of Russian cluster munition strikes on civilian infrastructure. These include both Soviet-era 9N210/9N235 submunitions from BM-27 and BM-30 rocket systems, and cluster-variant Iskander ballistic missiles.tml">Iskander ballistic missiles.

Russia's use of cluster munitions against civilian areas is one of the most documented categories of international humanitarian law violations in the conflict. The asymmetry — where Russia faces no legal or political constraint on cluster munition use, while Ukraine faced significant international pressure even to use DPICM on Russian military positions in Ukrainian territory — was noted by many analysts as a significant imbalance in the humanitarian law discourse around the war.

The Legal Framework: Convention on Cluster Munitions

The Convention on Cluster Munitions (CCM), adopted in 2008 in Oslo and entered into force in 2010, prohibits all use, production, stockpiling, and transfer of cluster munitions. As of 2026, it has 111 state parties. Neither the United States, Russia, Ukraine, China, India, nor most of the world's major military powers have signed it — making it somewhat analogous to the Ottawa Mine Ban Treaty in being a significant but not universal standard.

NATO allies who are CCM signatories — including the UK, Germany, France, and Belgium — publicly objected to the US DPICM transfer and reiterated their treaty commitments not to use, produce, or transfer such weapons. They did not, however, condition military aid or alliance cooperation on the US reversing the decision. The diplomatic friction was real but did not materially affect coalition cohesion.

Legal scholars debate whether transfer by a non-party (US) to another non-party (Ukraine) for use in operations against a non-party (Russia) has any bearing on CCM obligations. The consensus is that signatories are themselves compliant and the US-Ukraine transfer does not implicate their treaty obligations, though political opposition remains.

Post-War UXO Legacy: The Long-Term Concern

Ukraine faces an immense unexploded ordnance challenge regardless of cluster munition use — it is already the most mined country in the world, with thousands of square kilometers contaminated by Russian anti-personnel and anti-tank mines, Russian UXO, and Ukrainian defensive mines. The DPICM contribution adds to this challenge in contested territories.

International demining organizations estimate Ukrainian UXO clearance will take decades and cost tens of billions of dollars. Dedicated cluster munition sub-munition clearance is technically more labor-intensive per unit area than larger UXO because of the small size and wide dispersal pattern. Post-war agricultural land recovery in contaminated areas is significantly delayed by UXO risks.

These long-term concerns reinforced the argument for limiting DPICM use strictly to military positions and avoiding use in areas likely to be populated upon liberation. Ukraine's stated policy was consistent with this approach, though implementation verification in a combat environment is inherently difficult.