i would argue, if any party, group, organization, state intentionally blows up civilian infrastructure, it is either a terrorist attack and/or a war crime.

if it is by a state, then it could be considered 'aggression' -- the 'supreme international crime'.

as for the no direct / immediate civilian casualties part ("dubious") -- we can think of myriad examples of terror attacks and war crimes where the vast majority of civilians dying as a result of said attacks came later, even from 'indirect' causes -- dresden, hiroshima, nagasaki, al-shifa, etc.

but whether you decide to classify it as a terror attack, terrorism, war crime, or something better or worse, i think we should be consistent, regardless of who the perpetrator(s) is/are.

My quick definition of terrorism is (loose translation): systematic violence for political gain.

A terrorist attack is an attack perpetrated in a terrorist campaign. I don't think this really qualify, but i guess i could see why.

It could be a war crime though.

Destroying "civilian" airports, bridges, ports, transformers, water towers etc infrastructure is sort of standard practice in war though -- I doubt the states actually waging war are willing to consider those war crimes.

Russia is at war with Ukraine. so Ukraine did it?