Blowing up dams--even if the dam is a military object--is a specifically enumerated war crime under the Geneva Conventions, if attacking that object would cause the release of dangerous forces (specifically: flooding) that attacks or could cause severe losses to the civilian population

@Pwnallthethings

It is a war crime specified in Additional Protocol I to the Geneva Conventions.

Putin withdrew Russia from the ratification of Additional Protocol I in 2019.

@Leszek_Karlik @Pwnallthethings

Russia withdrew the declaration made by the Soviet Union--of which it is the state successor--at the time of its ratification of Protocol I, not its ratification of the Protocol as a whole. Cf: https://ihl-databases.icrc.org/en/ihl-treaties/api-1977/state-parties/ru

Accordingly, Russia remains bound by Art 56 of the Protocol banning attacks against dams and other "works and installations containing dangerous forces".