Although it remains not yet confirmed exactly how the dam was blown, it is the Russian military who, cynically, would probably think they have the most to gain.
Ukraine will have to deal with a destroyed dam plus the long-term environmental and humanitarian consequences. Experts fear it will wipe out islands in the delta and low-lying settlements, mostly on the southern bank. There are about 16,000 people estimated to be in the critical zone on the Ukrainian side of the river. Such predictable impacts mean it is likely to be a war crime, as defined in the Geneva conventions, if its breach causes "release of dangerous forces and consequent severe losses" to civilians.
The obvious military point is that Russia feared an amphibious attack across the Dnipro delta. Some of Ukraine's armed forces have been receiving marine training from the UK, suggesting that, at the very least, Kyiv wanted to keep the option open of trying what would have been a relative risky attack that, if successful, could have opened up the option of a more direct strike towards Crimea – or diverting Russian forces away from the southern front further east in Zaporizhzhia and Donetsk regions.
Russian defensive positions downstream, as mapped from satellite imagery, have already been concentrated on higher ground. The breach of the dam is an uncertain event, and it will take some days before it is clear where the new river line will be – and whether the fortifications are in appropriate positions.
Widening the Dnipro River from hundreds of metres to several kilometres makes the task of crossing in strength all the harder at the delta. Russia still has its air force available to make a river crossing difficult, and as the battle for Kherson in November showed, it is difficult to keep a bridgehead across the country's central river supplied.
However, it is also the case that the river is likely to narrow upstream, south of Zaporizhzhia. That may also create some military opportunities for Kyiv. What is certain is that as with the impact on civilians and the environment, all the consequences are some way from being played out.
Russia-Ukraine