Russia has been accused of hacking and/or electronic spying by other states.
North Korea has been accused of hacking and/or electronic spying by other states.
And yes, the US and quite a few European states -- and many other countries -- have also been accused of hacking and/or electronic spying by other states[a].
All these governments are playing with explosives: The right spark at the wrong place at the wrong time can start a fire.
Seemingly "minor" incidents have triggered wars in the past.[b]
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[a] Including via highly-targeted malware such as https://en.wikipedia.org/wiki/Stuxnet
[b] For example, https://en.wikipedia.org/wiki/Pig_War_(1859) , https://en.wikipedia.org/wiki/Marco_Polo_Bridge_Incident , https://en.wikipedia.org/wiki/Football_War , https://en.wikipedia.org/wiki/Assassination_of_Archduke_Fran... -- to name a few off the top of my head.