Like other aspects of war I think this also depends on variables.

Was it war when German Uboote sank our supply ships enroute to the UK? Not for a while. Was of war when Iran captured US navy seamen in the Arabian gulf?

Is it war when NoKo does the Sony hack? If they start shelling SoKo and they also pull some “cyber” to use military lingo, then it’ll probably be war. In the meantime it’s more like spying/sabotage (which can be part of war, but by themselves aren’t)