It seems like the clandestine nature of these attacks gives enough plausible deniability for the nations to not pick up arms. China has done a few comparable at

It seems like the clandestine nature of these attacks gives enough plausible deniability for the nations to not pick up arms. China has done a few comparable attacks on US assets, but the US hasn’t escalated on those in the past. Personally I think if one of these cyber attacks either hit a large/important enough civilian target, like shutting down a power grid for days, or a reasonably important military target, like a helicopter midair or something, then escalation might happen, but hard to say