Break the Taboo: Cluster Munitions Needed by Ukraine, Poland, and NATO [OPINION]

Ukrainian M777 Howitzer of the 44th Hetman Danil Apostol Artillery Brigade.
Ukrainian M777 Howitzer of the 44th Hetman Danil Apostol Artillery Brigade.
Photo. Ukrainian Ministry of Defence

Ukraine is facing a shortage of western artillery munitions. The artillery systems are also facing significant wear and tear, as Russia mobilizes its assets. Large-scale deliveries of cluster munitions could be seen as a potential and major reinforcement of the capabilities available to Kyiv. This would require a political decision, and a taboo topic to be scrutinized - also at NATO.Capabilities carried by cluster munitions may also be valuable for Poland.


After 9 months of the war, the Ukrainian artillery has become one of the primary assets on the battlefield. The artillery component has also been reinforced by NATO nations in an unprecedented manner. Not only does it include Post-Soviet systems, such as the Gvozdika howitzers delivered by Poland, but also systems that fire standard NATO calibre rounds.


NATO-standard US systems (155 mm M777, and 105 mm M119 howitzers), Polish howitzers (155 mm Krab howitzers), Dutch and German systems (155 mm Pzh 2000), Italian assets (155 mm M109, FH-70), French howitzers (155 mm Caesar), and systems delivered by other nations all participate in operations in Ukraine. The western artillery systems are praised by the Ukrainians as ones having the advantage over the post-soviet guns operated by them previously, and ones currently operated by the Russians. There is no doubt that the western guns played a key role in counterattacks near Kherson, Kharkiv, and Izium. Kyiv is facing several issues here though.

First, there have been too few deliveries, when considering the actual requirements. Ukraine most probably received no more than 200 155 mm towed artillery pieces, and no more than 150 self-propelled systems firing rounds of that calibre. This may seem a lot, but on the canvas of the requirements, considering the rapid expansion of the Ukrainian Armed Forces, and their dependence on the artillery. Ukraine also can only use air assets to a limited extent. It is much more dependent on artillery then.


The use and depletion of the munitions stockpile is another problem. The profile of the conflict and the intense use of artillery assets means that the assumed use has been greatly exceeded. It is estimated that the Ukrainians fire 5-6 thousand rounds per day, but this refers to a great variety of artillery rounds, also those not matching the NATO standard. The above means that the western states are burdened with munitions deliveries more and more. It is even more pronounced, as there was not a lot of artillery munitions procurement being done. The re-establishment of industrial capacity cannot be accomplished overnight. For instance, the US is increasing the number of 155 mm artillery projectiles from 14 thousand per month last year, to 20 thousand per month in spring this year.

The third problem is the issue of losses and wear of the artillery systems themselves. Kyiv has already lost a number of the western howitzers. Those that remain in service are worn out and require overhauls. It is becoming increasingly more challenging for the West to deliver new artillery assets, as it takes 2-3 years to manufacture them, while the available stockpile is finite. By no accident have the Americans begun to deliver 105 mm artillery pieces, alongside the 155 mm ones.

Everything above is happening as Russia is getting ready for another wave of mobilization, willing to expand its armed forces in a “Soviet” manner, with Divisions being formed, instead of compact brigade-level elements. Moscow wants to fight in mass, with the involvement of huge military units, also taking high losses into account. Copying the western model, with a greater level of autonomy granted to low-level commanders, or efficient communications and PGMs has not been a success for the Russians, which has been shown at the beginning of the war.

The Ukrainian authorities, ranging from President Zelensky, Defence and Foreign Ministers, to the Chief of General Staff, General Zaluzhny, all mention the threat of escalation and a Russian offensive that could happen during the upcoming months. Reinforcing the artillery, and delivery of western jets, main battle tanks, or IFVs (with decisions already made in the latter case) is one of the key postulates made by the Ukrainians. The howitzer artillery assets stockpile remains limited, as mentioned above. It is also difficult to replenish. A similar scenario applies to 155 mm PGMs, such as Excalibur, or SMArt 155.

Cluster Munitions - HIMARS-delivery-like-Breakthrough

Delivery of conventional cluster munitions to Ukraine may be a way out. DPICM - Dual Purpose Improved Conventional Munitions offer much more lethality against enemy troops of armour, as opposed to conventional HE rounds.

The principle of operation is quite simple. Several or even several hundred HE/frag submunitions are usually spread over a target.

M777 submunitions. Several hundred of those are carried in the M26 MLRS rockets.
M777 submunitions. Several hundred of those are carried in the M26 MLRS rockets.
Photo. Jack E. Hammond via Wikimedia Commons

The explosive power of those munitions makes it possible to effectively attack enemy vehicles, by penetrating the top armour, or the infantry, across a much vaster area than in the case of a conventional HE round. The same mission can be accomplished with fewer assets, firing a smaller number of rounds. And the losses inflicted on the enemy are greater, as some are unrecoverable, along with damage taken by vehicles. These advantages of cluster munitions would be especially useful in Ukraine, during a high-intensity conflict, where the artillery plays a significant role, with a high risk of experiencing counter-battery fires.

All those matters made the 155 mm cluster munitions, and cluster MLRS rockets one of the primary tools that could have made NATO artillery capable to push back the Warsaw Pact’s offensive. If Kyiv received more cluster munitions, this would have an effect tantamount to a transfer of more artillery assets.

So far, despite the requests made by Ukraine, as CNN or Politico reported, the US has not decided to take such a step. A small batch of Western cluster munitions was reportedly delivered to Ukraine. Most of the European allies do not own conventional cluster munitions now.

Why did the West get rid of most of the cluster munitions?

The use of cluster munitions usually entails significant collateral damage, with unexploded ordnance left behind (up to 20% of submunitions do not explode). These pose a major threat to civilians, as the proxy-war experience shows. Back in 2008, a cluster munitions ban has been adopted in Oslo, signed by more than 100 nations, including most of Western Europe: France, Germany, the UK, Spain, and so on. This brought the manufacturing of cluster munitions to a halt, with all of the stored munitions as such being destroyed by the signatories. Germany alone got rid of more than 300 thousand 155 mm artillery rounds, and dozens of thousands of M26 rockets. The convention was not signed by Poland, Romania, Turkey, Greece, Israel, the US, Russia, and China.

The adopted convention made it more difficult for those who did not sign it to maintain the manufacturing capacity when it comes to cluster munitions. Poland is the best example here. As we were told by Brig. general. ret. Jarosław Wierzcholski, Poland ceased manufacturing of the 122 mm MLRS Feniks-Z cluster rockets, once France declined to deliver rocket motors for these.

The Western financial institutions and NGOs also pressured defence companies in states that did not sign the convention to stop manufacturing.

WR-40 Langusta MLRS.
WR-40 Langusta MLRS.
Photo. Jarosław Ciślak/

The United States does not manufacture conventional cluster munitions. Some of the stockpiles have been destroyed, but a certain quantity is still available, should the use of such rounds be necessary. Steps have been made aimed at developing a collateral damage-free alternative. GMLRS AW warhead, carrying 182 thousand pre fragmented elements is a good example here. A small batch of BONUS munitions with 2 guided submunitions has been procured - meeting the convention requirements given the small number of submunitions, and the guidance system. Work has been launched aimed at developing the guided XM1180 artillery rounds (155 mm) designed to act against armour with direct hits, while the XM1208 round supposedly is to feature 9 smart submunitions that can be used against soft targets.

These assets cannot fully replace cluster munitions, given the requirements emerging in high-intensity conflict scenarios. Some assets (such as two types of 155 mm artillery munitions mentioned above) are being developed now. We do not know whether their capabilities would make it possible to completely replace conventional cluster munitions. We know, however, that these would be very expensive (as they feature guidance units), and challenging to use within the scope of logistics. For instance, different munition types would be used for different purposes.

One-shot-one-kill PGMs have been designated as an alternative for cluster munitions. There are not enough 155 mm artillery PGMs available, considering the necessity to neutralize more and more “waves” of the Russian forces. The Americans alone have provided Ukraine with at least 4,700 Excalibur rounds, constituting more than 25% of the total quantity available. The European states are also supplying BONUS and SMArt precision anti-tank munitions to Ukraine. All of those systems have played a key role in the fights of late 2022. The stockpile here, however, is finite.

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A small number of PGMs shall be conserved to act against high-value assets, such as air defence systems, artillery, or MBTs. Mechanized infantry, equipment storage areas, or other area targets are more suitable for being destroyed with the use of cluster munitions. Given the fact that M777 or Krab systems operated by Ukraine are relatively accurate, there would be no need to fire a lot of cluster munitions anyway. With effective fire control, a salvo of a small element, platoon, or an incomplete battery (3-4 guns, 3-4 rounds each) would be entirely sufficient to destroy (not just to neutralize) enemy mechanized units, or infantry elements. HE rounds are much less effective.

Cluster munitions meanwhile, entail a risk of unexploded ordnance, potentially posing a threat to civilians. Operationally speaking, however, there are no good alternatives for the cluster munitions used by the artillery assets. Meanwhile, the Russian occupation is the most significant threat to civilians. Tortures and executions or deportations have become a norm, breaking all international conventions. Ukraine, meanwhile, is suffering from major losses - military and among civilians.

It is a risk that needs to be taken, as even the Ukrainians are requesting cluster munitions to be delivered. Firing several 155 mm rounds would be as dangerous as 1 or 2 227 mm MLRS rockets - and these are usually fired in salvos, for instance: 72 rockets from 6 launchers, 12 rockets each, while each of the rockets carries up to 644 submunitions. A standard US-made M864 artillery round carries 88 submunitions. A short salvo of a 4-howitzer platoon (4 rounds each) is less than 25% of the potential unexploded ordnance that could be created following a salvo fired by a single M270 MLRS launcher.

For the aforesaid reasons, Ukraine shall receive cluster munitions for tube artillery assets first. The tube artillery munitions shortage is the most painful. When it comes to PGMs used by the air assets, the manufacturing capacity is more significant (up to 45 thousand JDAM kits per annum, as opposed to a couple of thousand Bonus or Excalibur rounds, if the US budget documents can be trusted). At the same time, the use of such weapons would be limited, considering the different nature of air operations, and artillery engagements. And that would not change, even if Ukraine receives the Western fighter aircraft.

When it comes to the HIMARS rockets, the cluster warhead rockets have less range (30 or 45 km, as opposed to 85 km for GMLRS). We also do not know if they remain in use. Furthermore, the M26 unguided rocket motors used in standard M270 MLRS systems can also be used to manufacture the GLSDB rockets, with a range of 150 kilometres. Finally, the M270 MLRS systems delivered by France, or Germany, are not tailored to fire cluster munitions, as the aforesaid states have signed the Oslo convention.

Tube artillery is what remains, and these assets are the most burdened ones, fighting at a distance of up to 30-40 kilometres (often less).

M119A3 towed howitzer.
M119A3 towed howitzer.
Photo. U.S.Army

Let us add that cluster munitions are also available for the 105 mm artillery assets. These could make the 105 mm guns very lethal, at shorter distances. There is not a broad range of PGMs available for those howitzers. These are available for 155 mm guns in small numbers. The 105 mm HE rounds meanwhile are much less potent than their 155 mm counterparts. One should expect that more 105 mm guns would be available soon. Delivery of lethal munitions for those would become increasingly more important. And that may be done through a transfer of cluster munitions that would allow the light howitzers to effectively act even against mechanized units.

Taboo Needs to be Broken

The Americans have not decided yet to deliver cluster munitions to Ukraine. It seems, however, that Kyiv needs this to achieve success on the battlefield. One may wonder whether the delivery of cluster munitions would contradict the legal obligations imposed on some of the nations supporting Ukraine. The Oslo convention includes Article 21 however that allows for military cooperation with states that did not sign the said document, also when it comes to cluster munitions.

It would be most beneficial to restart the manufacturing of cluster munitions, also in NATO member states that had previously signed the Oslo agreement. This would require the Convention to be terminated - here, a 6 months notice needs to be given. Politically speaking, this may be a major challenge.

On the other hand, many arguments support the potential recovery of such capabilities. When the Oslo convention was being signed, it was maintained that cluster munitions date to the times of the Cold War, while large-scale conventional wars are a thing of the past, while in expeditionary operations the cluster munitions may cause significant collateral damage. However, the full-scale war in Ukraine and the massive Russian mobilization have both shown that large-scale conventional conflict is still a present danger. One could even risk stating that the withdrawal of cluster munitions by NATO has contradicted Article 3 of the Washington Treaty, obliging the member states to establish a capability of self- and collective defence.

This was not intentional, as there was no risk of a war involving Russia close to the NATO border, or potentially with Russia attacking a NATO member state. The same applied to the risk of a full-scale conflict - this scenario was not even considered by the allies who signed the aforesaid agreement.

The solution - termination of the convention - may be criticized by those in favour of arms control. One should remember that Russia has also breached several international agreements when attacking Ukraine. These include the NATO-Russia Founding Act, the 1994 Budapest Memorandum, and even the UN Charter.

Moscow could be presented with an ultimatum, based on the 6 months of notice. Either the Russians stop posing a threat and withdraw their assets from Ukraine (not a probable scenario), or the Western states would be forced to reintroduce weapons allowing for effective self-defence, and provision of Ukraine with support in countering that threat.

Cluster Munitions in Poland

The discussion regarding cluster munitions can also be embedded in the Polish context. Poland has not signed the Oslo convention, but it ceased the manufacturing of cluster munitions more than 10 years ago. Given the limited availability of the necessary components (rocket motors from France), and the pressure imposed on the financial entities not to support manufacturing efforts as such, any cooperative undertakings are facing numerous obstacles. Let us add, that the Polish industry used to offer modern cluster munitions for 98 mm mortars, and 2S1 Gvozdika howitzers (Hesyt-1), with high performance, and reliability, much better than the Western counterparts developed a couple of decades ago. Therefore, the risk of the emergence of collateral damage, associated with the use of Polish munitions is much less significant.

A question emerges whether the manufacturing of such munitions should be restarted. The best-case scenario here would also involve an awareness campaign among the allies, who should appreciate the role and acknowledge the necessity to use munitions as such in combat. Since February 2022 we have known that assessment of security based on the notion of Russia working with the West, and the lack of a threat posed by a large-scale conventional conflict has been erroneous. The first symptoms of that could have been recorded 15 years earlier (Putin’s speech in Munich, war in Georgia). It’s high time to draw conclusions and establish relevant NATO defence capabilities and deliver relevant capabilities to Ukraine in parallel.

Commissioning of Krab, Rak, or K9 in the Polish Armed Forces provides a great opportunity to reinforce the relevant capabilities these assets provide, with the use of cluster munitions.

What about the risk posed by collateral damage? It exists. But collateral damage cannot be avoided in high-intensity conflicts, especially when we are facing an enemy who does not care about the losses, or the international conventions (whether that enemy has signed them, or not). Enemy occupation is far more dangerous for civilians, than cluster munitions, which has been proven by the conflict in Ukraine.

If the West replenishes its cluster munitions stockpile, a greater deterrence potential would become available, and thus the risk of a conflict with Russia would be greatly diminished. This is the primary goal that we shall all keep in sight.