Providing Ukraine with cluster munitions isn’t morally “flawed” – but denying them could be

This is the second installment of our mini-forum on the U.S. decision to furnish Ukraine with cluster munitions.  Your can find the first installment by Butch Bracknell here, and he expertly addresses the potential impact on allies. In the third installment (here) from Brian Cox addresses the decision’s implications for public relations and diplomatic engagements, to include “bringing focus to the methods that have been developed over the years to stigmatize cluster munitions

Dozens of 155mm Base Burn Dual Purpose Improved Conventional Munitions (DPICM) rounds wait to be loaded at a U.S. Army motor pool at Camp Hovey, South Korea September 20, 2016. U.S. Army/2nd Lt. Gabriel Jenko/Handout via REUTERS/File Photo

Providing Ukraine with cluster munitions isn’t morally “flawed” – but denying them could be

Last week (July 10) a New York Times editorial charged that “flawed moral logic” supported the U.S. decision to supply Ukraine with cluster munitions (or, as the Pentagon describes them, “dual-purpose improved conventional munitions, or DPICM”). 

The Times editorial is flatly wrong: as a group of experts put it–and I completely agree–the decision was necessary, legal and morally justified.  In this post we’ll unpack some of the details of this issue so you can decide for yourself.

What are cluster munitions?

The U.S. Department of Defense (DoD) Law of War (LoW) Manual describes them (¶ 6.13.1) as “munitions composed of a non-reusable canister or delivery body containing multiple, conventional explosive submunitions.” 

There are several kinds of cluster munitions and different delivery systems —cruise missiles, artillery, mortars, missiles, tanks, rocket launchers, or naval guns-but the U.S. is supplying shells that can fired by Ukraine’s 155mm artillery. 

A NYT’s report references, the two main 155-millimeter D.P.I.C.M. shells in the U.S. inventory are the M483, which contains 88 grenades, and the longer-range M864 which carries 72 grenades. Which version being considered for Kyiv is unclear.”  DoD explains these artillery rounds “disperse submunitions from the air, allowing Ukraine to target broad swaths of entrenched Russian troops and equipment.”  

The objection

The decision has generated controversy because some of the submunitions dispersed may be “duds,” that is, fail to detonate initially, but which may present a persisting lethal hazard to civilians because at some point in the future the bomblets might explode.

Thus, the Times editorial centers its moral objection on the “danger [cluster munitions] pose to civilians long after the fighting is over.”  The Times view aligns itself with human rights activists, as well as others including former President Donald Trump.  NBC News said “Trump repeated the argument made by many critics — including those on the left — saying unexploded cluster munitions “will be killing and maiming innocent Ukrainian men, women, and children for decades to come, long after the war.”

Of course, the possibility of future casualties from battle remnants is rightly concerning, but the question we’ll be examining is whether in this particular instance do they outweigh the costs–to include the moral costs–of denying Ukraine the weaponry?

The law: cluster munitions are not specifically prohibited or restricted by the law of war

What does the law say about these weapons?  Various pundits and others wrongly claim that cluster munitions violate international law.  This simply isn’t true.  As the DoD LoW Manual makes clear (¶ 6.13.1) Cluster munitions are not specifically prohibited or restricted by the law of war.”  

The cardinal principle

Of course, cluster munitions are subject to all the same targeting rules as any other weapon.  This includes, for example, the cardinal principle of “distinction” which means absent direct participation in hostilities, civilians cannot be targeted.  Moreover, all “feasible precautions” must be taken to protect them. 

In addition, if civilians are in the area of military objectives (e.g., enemy tanks or troops) and are at risk of being injured or killed in an attack upon then, such attacks are prohibited if they “may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated.” 


It is also prohibited to use weapons that are by [their] nature indiscriminate.”  Weapons are indiscriminate, the DoD LoW Manual tells us (¶ 6.7), if they “are incapable of being used in accordance with the principles of distinction and proportionality.”

Few weapons, including cluster munitions, are inherently indiscriminate.  Rather, it depends upon how they are used.  If cluster munitions targeted civilians or were used in situations where it was expected civilian losses would be excessive in relation to the military advantage anticipated, such uses would be unlawful, but unlawful use in a particular instance does not make the weapon itself illegal or prohibited from employment in other situations. 

As Human Rights Watch’s associate arms director Mark Hiznay told the Associated Press, the prohibition against “indiscriminate” attacks is  “not necessarily related to the weapons, but the way the weapons are used.”

Ukrainian commitments and other steps to minimize risk

Ukraine understands that how the weapons are used is critical to lawfulness, and has provided “the U.S. with written assurances that they will employ the capability responsibly, and that they will not use the rounds in civilian-populated urban environments.”

Other steps are also being take to minimize risk to civilians.  The cluster munitions being supplied, the Pentagon insists, “have been assessed to have a dud rate, or rate of unexploded submunitions released from each round, of 2.35%” (as compared to the30-40% failure rate of Russian submunitions already littering the battlefields).

Convention on Cluster Munitions

A scholar points out that “[c]oncern over the risk to civilian harm led in 2008 to a Convention on Cluster Munitions, which bans their use, production or sale by member states.”  However, the Convention is binding only on the parties to it, and since the U.S., Ukraine, and the Russian Federations are not parties, they’re not bound by it.

The Times editorial seems to think the decision to furnish Ukraine with cluster munitions is morally flawed because they are “a weapon that has been condemned by a majority of the world’s nations.”  The Cluster Munition Coalition says “123 states have joined the convention, of which 110 are States Parties and the remaining 13 are signatories that have yet to ratify.”  It is true that many of them are friends and allies (but how morally impressed should we be that Cuba is a party to the Convention?)

Obviously, this means there are more than 70 countries who have not signed, let alone ratified the Convention.  People need to be cautious about casting moral aspersions too widely on nations simply because those countries assess their defense needs in a dangerous world as requiring retaining lawful weapons that other nations facing different threats eschew. 

In this case the non-parties include Israel, Poland, Finland, South Korea, Greece, Turkey, Romania, India, Brazil, China, Egypt, Bangladesh, and Singapore, and they are nether America’s enemies. nor are they morally bankrupt societies. (But, yes, non-parties also include such potential adversaries as China, North Korea, Iran, Syria and, as already mentioned, Russia.)

A better moral question for the United States, which has responsibilities for the defense of a quarter of humanity, is whether it is ethical to ask troops to forego a lawful, available, and effective weapon in a potential conflict with an opponent armed with it simply because other, uninvolved countries don’t use it ? 

Shouldn’t there be a moral imperative to seek lawful technologies that can save lives–and limbs–of the militaries of democracies if they can help battle ruthless authoritarian regimes?

Simply counting ratifying governments doesn’t necessarily tell you as much as the Times editors seem to think.  Notably, those nations who are not yet parties represent eight of the ten most populous countries in the world (including Indonesia which has signed but not ratified).  Thus, it could very possibly be true that the regimes who are non-parties actually govern more people than those who have ratified. 

Protocol V to the Convention on Certain Conventional Weapons

The U.S., Ukraine, and the Russian Federation are all parties to Protocol V to the Convention on Certain Conventional Weapons.  Among other things, this treaty obliges parties ” to the maximum extent possible, record and retain information” about the use of certain weapons, including cluster munitions to as to facilitate the removal of any “explosive remnants” such as duds.

It does not appear there will be any issue with Ukraine complying with the Protocol. Ukraine’s Defence Minister Oleksii Reznikov said “Ukraine would keep a strict record of their use and exchange information with its partners.”  Additionally, the Pentagon advises that “Ukraine has also committed to mine clearing efforts once the conflict ends to further minimize the potential impact of the rounds on civilians.”    

U.S. Domestic policy and law

The Congressional Research Service (CRS) advises, that the U.S. “has historically defended the use of cluster munitions.”  Nevertheless, in 2008 the Obama Administration issued a new policy which was an “unwaiverable requirement that cluster munitions used after 2018 must leave less than 1% of unexploded submunitions on the battlefield.”

However, in 2017 a revised policy was issued which allowed “[c]ombatant commanders can use cluster munitions that do not meet the 1% or less unexploded submunitions standard in extreme situations to meet immediate warfighting demands.”

The 2017 policy did prohibit the “transfer cluster munitions except as provided for under U.S. law.”  Furthermore, the Washington Post says in its appropriations for DoD for the last seven years, Congress did not establish a waiver provision for the 1% dud rate limit.  However, the Post also finds that the Administration found a workaround:

“Biden would bypass it and Congress, according to a White House official, drawing down the munitions from existing defense stocks under a rarely used provision of the Foreign Assistance Act, which allows the president to provide aid, regardless of appropriations or arms export restrictions, as long as he determines that it is in the vital U.S. national security interest.”

To summarize, there is no domestic or international law prohibiting the U.S. from providing Ukraine with cluster munitions or, for that matter, any bar to the Ukrainians using them in a manner consistent with the law of war.

The enormous warfighting challenge the Ukrainians face

Yesterday (July 18) Secretary of Defense Lloyd Austin said “Ukraine is fighting for its life.”   Virtually all military analysts agree that the military challenge the Ukrainians face in their effort to recapture territory lost to Russian aggression is stunning.  Though the Russian military has not fared well against a Ukraine aided by billions of dollars of equipment and other assistance from the U.S., NATO, and other non-NATO countries, it is dangerous to underestimate them. 

It is one thing to operate on the defensive, and quite another to conduct an offensive campaign as the Ukrainians are now trying to do. Military experts will tell you that conducting offensive operations against an entrenched enemy requires at least a 3 to 1 advantage in troop strength and military equipment.  It does not appear that Ukraine has those kinds of numbers.

A particular problem for Ukraine’s military is that Russia–which has competent engineers—has had months to build extensive field fortifications.  Moreover, the Russians have had time to think through their defensive plan, fire support procedures, minefield design, ambush opportunities, booby traps, killing fields, etc.  According to a June 2023 report from the Center for Strategic & International Studies:

“Russia has constructed formidable defensive fortifications in eastern and southern Ukraine. These defenses consist of an extensive network of trenches, antipersonnel and anti-vehicle mines, razor wire, earthen berms, and dragon’s teeth—truncated pyramids made of reinforced concrete used to impede the mobility of main battle tanks and mechanized infantry. As one UK defense intelligence report concluded, ‘Russia has constructed some of the most extensive systems of military defensive works seen anywhere in the world for many decades. These defences are not just near the current front lines but have also been dug deep inside areas Russia currently controls.'”

Mines have significantly increased the lethality of the Ukrainian battlespace.  How many mines?  In the current issue of Strategy & Tactics, retired U.S. Army colonel Gilberto Villahermosa explains that Russia is “using hundreds of thousands [of landmines] in front of and throughout their defensive positions.”  Here’s another recent media report:

“With an immense arsenal of mines at their disposal, the Russians have landmined Ukrainian territory at an unprecedented rate, making it one of the largest minefields in the world. It’s estimated that approximately 170,000 square kilometers are now covered with anti-tank or anti-personnel landmines, which is about the size of Florida, or almost six times the surface area of Belgium.”

Ukraine has been struggling to deal with the Russian minefields.  In a July 9th article (Sappers risk their lives to win Ukraine back, inch by inch) the Economist explains what Ukrainian military engineers (“sappers”) trying to penetrate Russian defenses face:

“The Ukrainian sappers given the job of finding a way through have to deal with around 1,500 mines per square kilometre. That is before Russian artillery, drones, aviation and electronic warfare begin their work. “Sappers have become target number one,” says “Sleepless”, the company commander….”

Even with these courageous efforts things can go terribly awry. War correspondent Andrew Kramer reported a few days ago (July 16) about a grisly scene as Ukrainian troops attempted to deal with Russian defenses composed of a “vast array of mines, trip wires, booby traps and improvised explosive devices”:

“One Ukrainian soldier stepped on a mine and tumbled onto the grass in the buffer zone between the two armies. Nearby lay other Ukrainian troops, their legs in tourniquets, waiting for medical evacuation, according to videos posted online and the accounts of several soldiers involved.”

“Soon, an armored vehicle arrived to rescue them. A medic jumped out to treat the wounded and knelt on ground he deemed safe — only to trigger another mine with his knee.”

Kramer explained how complicated advancing through minefields can be.  Even after deminers clear a path “Russian forces often fire rockets that scatter small, hard-to-spot green plastic ‘leaf’ mines, also called butterfly mines, over the cleared area.”  He related an especially heartbreaking story about a Ukrainian doctor who had to amputate “both hands of a demining expert who was wounded while trying to defuse a booby-trapped mine.”

Yesterday (July 18) the Washington Post detailed yet another challenge for the Ukrainians:

“Another important feature of Moscow’s defenses are the omnipresent drones that provide Russian forces granular, real-time information about Ukrainian troops’ whereabouts, enabling them to conduct kamikaze attacks or tee up targeted strikes, a challenge that not even American forces — for all their combat experience in recent decades — have faced on this scale.”

While neither side in the Ukraine conflict has gained air superiority, Business Insider reports that Britain’s top air force general said Russia’s air force “remains largely intact.”  It also cited a Ukrainian pilot who “says its air force is so outclassed by Russia’s that it can ‘do nothing to them in the air.'” 

It is no exaggeration to say the Ukrainians are confronting the most difficult military challenge Europe has seen since World War II.  Is it really “morally flawed” for them to want to use a lawful weapon to try to improve their chances of being successful in retaking their territory?

The myth of near-term battlefield habitability

Perhaps the most ‘intellectually’ flawed premise the Times, Trump, and the other critics rely upon is the idea that if the Ukrainians could be prevented from getting cluster munitions, battlespaces in Ukraine could quickly return to being farmer’s fields or glens where children could play.  Nothing could be further from the truth.

Even if no–literally “zero”–cluster munitions were used, battlefields–particularly like those in Ukraine where intense fighting has taken place–are literally lethal hellscapes where death or injury can come in a myriad of ways. They take years or even decades to remediate and make safe.

Why?  Even without “duds” from cluster munitions, battlefields can still be littered with abandoned (but still usable) weapons and ammunition, razor sharp shrapnel from conventional weapons, leaks of toxic chemicals from wrecked vehicles and buildings, biological hazards from rotting corpses, and the threat of teetering structures damaged by the fighting.  Moreover, there will be duds from ordinary artillery shells and bombs.  Indeed,  unexploded conventional ordinance from WW II is still being discovered.

Anyone who lets civilians, let alone children, traverse a battlefield before it is thoroughly cleared by experts could find themselves charged with negligent homicide.

A particularly vexing issue for the Ukrainians will be the hundreds of thousands of anti-tank and anti-personnel mines that have been strewn across the country by Russian forces.  De-mining operations are dangerous, costly, and lengthy.  It will take years, if not decades, to fully demine many areas of Ukraine.

Consider that in the 1982 Falklands/Malvinas War the Argentinians laid about 30,000 landmines–which is just a fraction of the hundreds of thousands the Russians (and Ukrainians) have laid.  Nevertheless, demining operations weren’t completed until November 2020, more than 38 years later.

As to cluster munitions, National Security Advisor Jake Sullivan pointed out the Russia had already extensively used them – despite a dud rate “between 30 and 40 percent.”  He added:

“Russia has already spread tens of millions of these bomblets across Ukrainian territory.  So we have to ask ourselves: Is Ukraine’s use of cluster munitions on that same land actually that much of an addition of civilian harm, given that that area is going to have to be de-mined regardless?”

He’s absolutely right.  Whatever factual resonance the notion that “dud” cluster munitions contaminate battlefields and put at risk civilians who may wander onto them might have in other circumstances, it simply doesn’t apply to where it is expected Ukraine will use the weapons.  These areas are already infested with lethality, and the same techniques to clear them of the mines and other hazards now present will also address any “dud” cluster munition submunitions.

In truth, there is little evidence that “duds” from Ukrainian cluster munitions will add significantly to the existing risk civilians or friendly forces face on Ukrainian battlefields already fouled with multiple perils.

Why cluster munitions?

There is, however, much evidence indicating that cluster munitions would be especially helpful to Ukraine.

Ready availability

In a new report, the Economist quoted experts who dubbed artillery as the “quintessential weapon” of the Ukraine War.   On July 11, Newsweek quoted an authority as saying “Russia is firing at least four times as many artillery shells as Ukraine…20,000 rounds per day for Russia is a low estimate, as is 5,000 rounds per day for Ukraine.” 

Still, the Ukrainians have also proven to be formidable artillerists–so much so that their ammunition consumption according to the Economist, “has far outstripped both pre-war expectations and production capacity, exposing gaping holes in the West’s industry.”  Unsurprisingly, CNN said yesterday that the “US and Europe are struggling to provide Ukraine with the large amount of ammunition it will need for a prolonged counteroffensive against Russia.” 

Why the shortage?  NATO simply “did not adequately prepare for the possibility of a protracted land war in Europe following decades of relative peace.”  It is true that production has increased markedly as the Army told CNN that the U.S. is now producing “just under 30,000 shells monthly.”  However, that number translates to only about six days of Ukraine’s needs at its current burn rate.

National Security Advisor Sullivan was frank when he conceded, as did President Biden, that U.S. stockpiles of unitary artillery rounds (those without submunitions) were “running low.” 

“So, for us, when it came down to the choice, our choice was: Despite the difficulty, despite the challenges, despite the risk to civilian harm associated with cluster munitions, the risk to civilian harm of leaving Ukraine without the ammo it needed was, in our — from our perspective, greater.”

Thus,  the Ukrainians need artillery ammo, and though the low on unitary artillery rounds, it has has nearly three million [DPICM] rounds in its inventory.”

Unique capabilities

There are plenty of purely military reasons for the Ukrainians to use cluster munitions in the specific situation they find themselves.  The Times says the decision to provide the additional shells:

“[G]ives Ukrainian troops more time to probe the Russian defenses for weak spots along three main lines of attack — shelling Russian artillery that attacks their advancing forces — and then punch through dense minefields, tank traps and other barriers. It also allows the Ukrainian Army to do more of what it knows best — fire thousands of artillery shells a day to wear down Russian defenders.’

The Royal United Services Institute for Defence and Security Studies (RUSI) says the “military utility of these munitions to Ukraine is clear.”  RUSI explains:

“When fired against Russian defensive fortifications in Ukraine, a conventional artillery shell has a very low probability of killing Russian troops unless it lands directly in a trench. Even if an HE round does land in a trench, it will only spread shrapnel in the trench sector within line of sight of the point of detonation. A DPICM round, by contrast, spreads 72 submunitions over a significant area. This greatly increases the chances of multiple submunition blasts directly impacting troops in trenches, providing much greater lethal and suppression effects.”

This tracks with an article in Task & Purpose where journalist Jeff Schogol quotes a number of experts as to why cluster munitions are especially suited for the military situation Ukraine faces.  These include retired Army general (and previous LENS conference speaker who earned his PhD at Duke) Robert Scales.  Scales, an artillery officer who commanded in combat, relates:

“Each DPICM round has a killing radius at least 10 times greater than a unitary round, Scales told Task & Purpose. Each of the submunitions, which are the size of flashlight batteries, falls almost vertically, meaning they will go down into trenches.”

“There are so many points of detonation, that they will almost always smother a trench line,” Scales said. “So, anyone hunkering down in the trench, thinking he is going to hide from the mortars or the artillery, is going to get wounded.”

Scales adds this vitally important point: ““If you’re trying to kill Russian artillery, most of which is still towed, [cluster munitions] are optimally suited for that role, as they were in the Gulf War.”

Finally, Forbes relates that an Army study shows that “cluster shells are four times as effective compared to unitary shells—with a single high-explosive warhead—when fired at a platoon of enemy fighting vehicles.”  Forbes also says:

“As a bonus, the study concluded, a howitzer battery firing cluster shells was more likely to avoid enemy ‘counterbattery’ return fire because it could destroy an enemy target faster—and thus could pack and up and leave before the enemy could triangulate its location.”

Conversely, if the counterbattery threat is low, ‘targets can be engaged in the same total time’ with DPICM shells versus unitary ones.”

The key is that cluster munitions have certain properties that make them especially useful to Ukraine in the specific circumstances of its current offensive.

Concluding thoughts

The most perplexing part of the Time’s editorial (and the similar complaints of Trump and the human rights community) is that the editors fixate on speculation that some time in the future Ukrainian civilians may be injured by “dud” ordinance, but they seem to be oblivious to the reality that Ukrainian civilians are now being killed and injured by Russian missiles and drones that are not “duds”

Other Ukrainian civilians are also suffering.   On July 13th the Associated Press reported that “thousands of Ukrainian civilians are being held in Russian prisons.”  It says “hundreds are being used for slave labor” and that:

Torture is routine, including repeated electrical shocks, beatings that crack skulls and fracture ribs, and simulated suffocation. Many former prisoners told the AP they witnessed deaths. A United Nations report from late June documented 77 summary executions of civilian captives and the death of one man due to torture.”

The absence of cluster munition ammunition at this stage of the Ukrainian offensive will inevitably cost the lives of Ukrainian soldiers.  Civilians will also suffer because the troops who will be lost are their spouses, siblings, parents, and friends, and there will be fewer people to fight to defend Ukraine.  National Security Advisor Sullivan was correct when he said:

“We recognize that cluster munitions create a risk of civilian harm from unexploded ordnance….But there is also a massive risk of civilian harm if Russian troops and tanks roll over Ukrainian positions and take more Ukrainian territory and subjugate more Ukrainian civilians because Ukraine does not have enough artillery. That is intolerable to us.”

The editorial concedes “it is Ukraine’s decision to choose what weapons it uses in its defense” but adds “it is for America to decide which weapons to supply” and counsels inaction.  But in this particular instance–where we are talking about lawful conventional weapons that are readily available and desperately needed–is inaction really moral, particularly when we know the suffering that it is ongoing?  Perhaps it is worth pondering John Stuart Mill’s observation in his 1859 essay, that a “person may cause evil to others not only by his actions but by his inaction, and in either case he is justly accountable to them for the injury.”

Of course, providing cluster munitions is no panacea as it is not likely the weapons will–alone–prove decisive.  And for many reasons, America may not provide Ukraine every weapon in its inventory.  Each request must be carefully considered on its own unique merits–as it appears this one was. 

But the naysayers’ objections to supplying cluster munitions center not on the legality, availability or potential effectiveness of the weapon but rather on the flawed notion that already dangerously lethal battlefields might sustain some additional measure of future deadliness. 

In this case such objections are seriously misplaced because the evidence overwhelmingly shows that the remediation already required to clear these sites of the existing infestation of Russian landmines and booby traps will necessarily encompass measures that will also neutralize any “dud” cluster munitions.  

To reiterate, denying Ukrainians cluster munitions now will hardly lessen the chances that civilians venturing into these perilous battlescapes will escape injury or death. 

The Ukrainians who are fighting hard to defend their families and their nation are keenly aware they will be living with the consequences of cluster munitions use.  They have every incentive to use them in a way that minimizes the risk to civilians.  Their view deserves respect.

Accordingly, providing these particular weapons to Ukraine is not “flawed moral logic.”  Rather, what would present it would be a the decision to deny troops of a rule-of-law democracy an available means to lawfully counter a brutal enemy.

Remember what we like to say on Lawfire®: gather the facts, examine the law, evaluate the arguments – and then decide for yourself! 

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