The Destruction of the Nova Kakhovka Dam and International Humanitarian Law: Some Preliminary Thoughts

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This morning the Nova Kakhovka dam in Ukraine was destroyed, in circumstances which remain unclear. Thousands of people are in peril, while the devastation of downstream communities and the environment will be immense. The dam appears to have collapsed, and the reservoir behind it is now draining at speed. In this post I will just briefly set out the relevant framework of international humanitarian law regarding attacks against dams, and how it applies to the facts as we know them. Last year my friend and colleague Mike Schmitt wrote up two very detailed posts on the rules governing attacks on dams on Articles of War, and I will direct readers to those posts for a more detailed examination of these rules (here and here).

(1) Attribution – as things stand it is not yet clear who destroyed the dam. Ukraine is accusing Russia of having done so, while Russia is accusing Ukraine. While all communities affected are on Ukrainian sovereign territory, many of them are in those regions that Russia controls and claims to have annexed. The harmful consequences of the destruction of the dam are such (including e.g. in disrupting water supply to Crimea) that from the mere fact of the dam’s destruction we cannot with certainty conclude who did it, or in whose interest it was to do it. Obviously to me it seems more likely that Russian forces destroyed the dam, but this is not  something that can simply be assumed.

(2) The relevant rules of IHL apply to “attacks”, and it is again not entirely clear whether there has been such an attack, defined by Art. 49(1) of Additional Protocl I to the Geneva Conventions as any “acts of violence against the adversary, whether in offence or in defence.” If the dam was damaged by Ukrainian shelling, as Russia claims, then this would qualify as an attack per Art. 49(2) AP I, which applies “to all attacks in whatever territory conducted, including the national territory belonging to a Party to the conflict but under the control of an adverse Party.” But if the initial damage to the dam was caused by Russia, e.g. by damaging a sluice gate which then in a catastrophic chain of events led to the collapse of the whole dam, it is somewhat less clear whether this event would qualify as an “attack.” Generally IHL does NOT regard as attacks the sabotage of a party’s own dam, as Mike explains in his second post. If, for example, Ukraine sabotaged a dam under its control in order to flood an area and prevent Russian troops from advancing, this would not be an attack on the dam in the sense of IHL, even if civilians died as a result. From Russia’s perspective the Nova Kakhovka dam is precisely in such a situation, especially because it was under its control – even if as an objective matter the dam and the whole territory is under Ukrainian sovereignty. Again I will reserve my judgment here, my point is simply that the existence of an “attack” in the sense of IHL is not an obvious issue.

(3) If there was an attack against the dam, it would violate IHL if it ran afoul of rules on distinction, proportionality, and precautions. (I will only deal here with the first two).

(4) On distinction, the issue is whether the dam was a military objective, and thus lost its protection as a civilian object. Per Art. 52(2) API, “military objectives are limited to 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.” There are two limbs of that test, which both need to be met. A dam is not a military objective by its nature, but it may be such by its purpose or use. The real question here is whether the dam was making “an effective contribution to military action.” For example, the road on the top of a dam can be used to transport military equipment or supplies, or the electricity generated could supply military facilities. On the facts that does not appear to be the case here. On the second point, destroying a dam can, in principle, offer “a definite military advantage”, e.g. by disrupting enemy movements through the affected area. Again, both limbs of the test need to be met – if the dam was not making an effective contribution to military action, it would not qualify as a military objective even if destroying it notionally offered some military advantage. The bottom line here is this – without knowing who destroyed the dam and WHY they did this, we cannot conclusively say whether the dam was or was not a military objective. To me it appears unlikely that it was, but this is not a possibilty that can be excluded. Note the relevance of the official statements of the parties to the conflict here – if both states deny that they destroyed the dam, that obviously undermines any claim that the dam was a military objective and that destroying it conferred a military advantage.

(5) On proportionality the situation is, I would submit, clearer. Under Art. 51(5)(b) AP I, an attack is disproportionate if it “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.” Again without knowing what the military advantage anticipated was (if any), we cannot make this assessment conclusively. But even on a generous assumption that (say) Russian forces damaged the dam in order to somehow disrupt the ongoing Ukrainian offensive, the extent of the destruction and damage to the civilian population and objects downstream is such that the attack was in all likelihood disproportionate, and very clearly so.

(6) A dedicated provison of AP I, Art. 56, specifically regulates attacks on installations containing dangerous forces, such as dams. The upshot of this provision is that an attack would violate Art. 56 EVEN IF it was confined to a military objective and was proportionate under the more general targeting rules of IHL, if the attack “may cause the release of dangerous forces and consequent severe losses among the civilian population.” Two points are of key importance here regarding the destruction of the Nova Kakhovka dam – whether losses among the civilian population (not objects) could be SEVERE, and whether this is something the dam’s destruction MAY cause. The severity threshold is vague, but is most likely crossed in a situation involving a risk to many thousands of people in areas that have not previously been evacuated. The scale of the impact is enormous – if this is not severe in terms of risk to civilian life, I fail to see what would be. The second point is that the risk threshold is lower here (may cause) in the context of Art. 56 than in a proportionality assessment. Bottom line – if there was an attack against the dam (which again is likely but not obvious), it almost certainly violated Art. 56, regardless of considerations of distinction and proportionality. Art. 85(3)(c) AP I further provides that such an attack could amount to a grave breach, i.e. a war crime, but the definition of the breach is such in terms of its mens rea requirements that it is difficult to distinguish from a ‘vanilla’ disproportionate attack.

(7) President Zelenskyy has used the term “ecocide” to describe the dam’s destruction, an issue I will leave for another day. What I can say now is that, if it turns out that the dam was destroyed by Russian forces deliberately and that they did so without pursuing any definite military advantage and did so knowing of the harm that can befall the civilian population, the dam’s destruction could amount to a war crime or even a crime against humanity. Note that an action can constitute a crime against humanity even if it is not an atack in the IHL sense of the term (point (2) above). All this depends not just on the extent of harm to civilians, but on the intent of the relevant actors, which we cannot know with certainty at this time.

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Felix Tandler says

June 6, 2023

Couldn't it even be a strategical advantage for Ukraine to empty the kakhovka reservoir? After all, the lake itself was the most easily to defend part of the whole front, which could become much easier to overcome,as soon as the mud inside the basin dries out, and only the natural river itself remains as a major obstacle. Moreover the floodings downstream are just temporary.

Nicolas Boeglin says

June 6, 2023

Dear Professor Milanovic

Many thanks four your very valuable post.

Taking into consideration the fact that Ukraine has been announcing an imminent offensive for weeks, without Russia knowing where it will be concentrating its military efforts, I suppose that since the dam was bombed, the flooded zone is one where Russia is sure that the Ukrainian offensive will not take place.

I think that the ICC can begin its search for evidence incriminating Russia.

Yours sincerely

Nicolas Boeglin

Ralph Janik says

June 6, 2023

Excellent and impressively quickly written post (again). There's one thing I fail to understand about the attack-criterion tho: The Commmentary on AP I (art 49) explicitly says
"The definition given by the Protocol has a wider scope since it -- justifiably -- covers defensive acts (particularly "counter-attacks") as well as offensive acts, as both can affect the civilian population. It is for this reason that the final choice was a broad definition. In other words, the term "attack" means "combat action"."

So why should an attck on a party's own dam not be covered, as Michael Schmitt suggests when stating
"Article 56 only applies to “attacks,” a term of art in IHL. It would not bar the destruction of a Party’s own dam, for instance, to flood a potential avenue of attack by the enemy. Use of the term “attack” instead of “destruction” was intended to make this distinction clear-cut"

Hoffmann Tamás says

June 6, 2023

Dear Marko,

Thanks for your fascinating analysis.

Just two brief comments:

1. Art. 56(1) specifically mentions "severe losses among the civilian population", which seems to me different from "risk to civilian life" that you envisage.
While the commentary is not clear on this point, the language seems to suggest that the word loss refers to loss of life, not potential risk.

2. The Nova Kakhova dam has actually been used as a military supply route for quite a long time, which also makes it a potential military target:

See e.g.


James Schoettler says

June 6, 2023

Appreciated your post. Another point for discussion is potential liability under the law of occupation, including a possible grave breach for extensive destruction etc. under GCIV art. 147.

Marko Milanovic says

June 6, 2023

Many thanks for the comments.

Ralph, the 'attack' question really is quite complex. I have no firm view on it, except that I wanted to flag the problem. Which is essentially whether destroying a dam is an act of violence against the adversary. The book by Bothe et al cited by Mike discusses this in substantial detail, including the relevant drafting history, in particular Dutch and Belgian views that a party must be able to flood its own territory as an obstacle to an advancing enemy. Imagine, for example, if the Russians merely opened all of the sluices on the dam, allowing the reservoir to drain and flood the area downstream - surely that is not an attack against the dam, even if the effect was similar. If the water was being used to drown the enemy or the enemy's civilian population, rather than as an obstacle, then the water might be the means of attacking. Either way as I explained it is a non-obvious issue.


On your first point, Art. 56 is clearly anticipatory in character, because it governs the conduct of hostilities. It is not violated only if severe losses of life actually happen, but also if they may happen ex ante. An attack directed against an installation that may cause the release of dangerous forces is prohibited as such, even if somehow the forces are not released or people do not die. The point is precisely to mitigate risk. The notion of a severe loss of life was meant to exclude the destruction of dams or dykes in sparsely populated areas (again see the Bothe book cited by Mike).

On your second point, if the road above the dam was being used for military transport then this would make it a military objective from Ukraine's perspective. This is only on the assumption that the road was being used so in the relatively recent past, or there was information that it would be so used. I have no idea whether this was happening in recent weeks or months (the link you provide is rather old). Either way this would matter only if Ukraine destroyed the dam, not if Russia did so. And even if it was Ukraine, there would still be the rules governing precautions to contend with (e.g. if the road could have been disabled by other means) as well as the provision on the loss of special protection in Art. 56(2).

Final point -as the day is unfolding again a key point is that both parties deny that they destroyed the dam. This makes any reliance on military advantage or necessity difficult.

Marko Milanovic says

June 6, 2023


You are quite right about this. If the rules on attack don't apply for some reason, and if it was Russia that destroyed the dam, then certainly Art. 53 GC IV would apply. Under that article: "Any destruction by the Occupying Power of real or personal property belonging individually or collectively to private persons, or to the State, or to other public authorities, or to social or cooperative organizations, is prohibited, except where such destruction is rendered absolutely necessary by military operations." The criterion of absolute necessity here would encompass some kind of proportionality assessment in terms of harm to civilians.

ACE says

June 6, 2023

To add to your preliminary considerations:

Article 35(3) AP I: "It is prohibited to employ methods or means of warfare which are intended, or may be expected, to cause widespread, long-term and severe damage to the natural environment."

Article 1(1) ENMOD (Rus&Ukr parties): "Each State Party to this Convention undertakes not to engage in military or any other hostile use of environmental modification techniques having widespread, longlasting or severe effects as the means of destruction, damage or injury to any other State Party."

Hoffmann Tamás says

June 6, 2023

Dear Marko,

Thanks for the reply.

I'm afraid I'm not in complete agreement with you. The very text of the provision clearly suggests that while these works or installations enjoy a higher level of protection, that is not absolute and subject to the potentiality of severe losses among the civilian population ("if such attack may cause the release of dangerous forces and consequent severe losses among the civilian population").

The ICRC Commentary similarly provides that "2153 The works and installations concerned are civilian objects a priori, and may therefore not be attacked. If they become military objectives, as defined in Article 52 ' (General protection of civilian objects), ' they enjoy special protection and may not be attacked when such attacks may cause severe losses among the civilian population because of the release of dangerous forces. If such an attack cannot cause severe losses it is legitimate, provided that the works or installation which is attacked has clearly become a military objective in the sense of Article 52".

Hence, it indeed matters how we interpret the stipulation "may cause severe losses among the civilian population".

In this situation I submit that we should enquire about the likelihood of the potential of severe losses and not simply conclude that since the severity threshold is vague then it is automatically crossed by the fact that thousands of people have to be evacuated.

And this is where my second remark becomes important. While you dismissed it by stating that the link is old, it seems that the Nova Kahovka dam's bridge was one of the very few crossings to the other bank of the Dnipro and as such, it had a huge military significance. This means that it could be seen as a military target by the Russians to prevent a Ukrainian offensive.

I'm not trying to claim here that the (presumably) Russian action was lawful. At the minimum, they definitely violated to take precautionary measures. Nevertheless, I think that the situation might be slightly more complex than you have suggested.


Marko Milanovic says

June 7, 2023

Many thanks Tamas. To be honest I'm not entirely sure that we actually disagree.

On your first point re the triggerring of the special protection of Art. 56 I had first understood you as saying that this rule only applies if people actually die as a result of an attack on such an installation. I explained that this is not the case, i.e. that Art. 56 applies prospectively and can be violated even if nobody dies. The 'may cause' language is clearly foresight/risk-based; I have not claimed that it applies whenever there is a tiniest possibility that people might die. But 'may cause' is emphatically NOT to be read as 'likely' for people to die. This is clear from the drafting history. I'm pasting here a part of Mike's second post that explains this:

"Additionally, Article 56 appears to impose a lower standard of certainty of harm than is the case with the proportionality rule. The latter requires consideration of “incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof” that “may be expected.” By contrast, Article 56(1) is triggered if an attack “may cause the release of dangerous forces.”

It would be overbroad to interpret the “may cause” text as denoting any possibility whatsoever. This is clear from the Bothe, Partsch, and Solf Commentary (they were participants in the Diplomatic Conference that drafted the Protocols), which notes that the drafting Committee elected to use “may” in lieu of “is likely” to raise the “standard of care to situations where the release of dangerous forces is objectively foreseeable rather than limiting it to cases where such effect is probable” (page 365). But the Article 56 standard certainly appears less demanding than that residing in the proportionality rule; the former would appear earlier along the uncertainty continuum than the latter (on targeting uncertainty, see here)."

On your second point, basically you are saying that the road on the dam could be a military objective by PURPOSE, i.e. its potential future use by Ukraine because of the road on the top of the dam. Sure, that's certainly possible. I flagged this possibility in my initial post. But then we get into precautions territory - in particular Art 57(2)(c) (warnings to civilian population) and 57(3) (is it possible to disable the road without destroying the dam).

More importantly, the special protection in Art. 56 cannot be removed simply on the basis of the dam's potential future use. Art. 56(2)(a) clearly requires past/present use on a more systematic level, because the protection ceases: "for a dam or a dyke only if it is used for other than its normal function and in regular, significant and direct support of military operations and if such attack is the only feasible way to terminate such support."

Thus, even if the dam was a military objective, the Art. 56 protection would not have ceased simply on the basis that, speculatively, at some future point Ukraine could have used the road on the top of the dam to transport its forces from one bank of the river to the other.

Anyway, as I already said the really difficult question here is the existence of an attack. We would generally not regard a party blowing up its own bridges to stop an enemy's advance to be an attack on that enemy (unless they were already on the bridge). The attack paradigm would clearly apply if Russia destroyed the same dam that was under Ukraine's control, but it is unclear if it applies here, for the reasons I have given.

Mike Howman says

June 7, 2023

Before judging either sides motives, remember that the RAF dambusters destroyed the Mohne dam in WW2. 1600 died in the flooding.

David Helms says

June 7, 2023

Do I get this right?

With regard to the water behind the dam does not make an effective contribution to a military action,as such, does not meet the definition of a "Military Objective"; therefore, the reservoir water is defined as a "civilian object".

Paula Silfverstolpe says

June 9, 2023

Thank you for excellent post.

It has been reported in media that the an interview with Washington Post last year, Maj. Gen. Andriy Kovalchuk, the initial commander of the Ukrainian counteroffensive in the Kherson region, admitted that HIMARS were used in a test strike on one of the dam's floodgates "making three holes in the metal to see if the Dnieper's water could be raised enough to stymie Russian crossings but not flood nearby villages,

I would be very interested in hearing your views on the legality of such operation if the report is true. This "test attack" would still be an "attack" as per IHL (AP I, art. 49(1)) with a a not negligible risk that it “may cause the release of dangerous forces and consequent severe losses among the civilian population.” (AP I, art.56)