Whodunit?

 

The Novaya Kakhovka dam has been blown up in Ukraine: who did it? Half the commentators are sure it was the Russians. Half are sure it was the Ukrainians. Both sides deny it.

Why would the Ukrainians blow up the dam?

It will cut off much of the water supply to Crimea.

It will flood some lowlands where Russian troops have defensive lines.

Why would the Russians blow up the dam?

It makes a Ukrainian counteroffensive across the Dnepr harder, by making the Dnepr wider and deeper.

It floods the centre of Kherson, the large city in the area, now in Ukrainian hands.

The Ukrainians seem likely to recapture the area soon. Better, then, to blow it up as they retreat, rather than hand it over intact and give more strength to Ukraine. The Russians have been targeting Ukrainian infrastructure elsewhere.

By contrast, why would the Ukrainians blow it up, if they expect to capture it, and will need it to rebuild their country?

According to the Ukrainians, the Russians already had the dam wired up for destruction; the Russians deny this. The Ukrainians claim it is not practical to blow a dam of that size with a missile strike. In any case, since they held the dam, it would have been easier for the Russians to blow it than the Ukrainians.

On balance, given all these calculations, it seems most likely that the Russians did it. 

Perhaps in impotent fury.