They broke into the Iranian nuclear program without much condemnation, so...
I still find it dismaying that we so casually accept this state of affairs. There is no meaningful difference between attacks like this and a foreign agent setting fire to the bank building or physically sabotaging the dam.
https://en.wikipedia.org/wiki/Stuxnet https://en.wikipedia.org/wiki/Flame_(malware)
Both of these were directed primarily at Iran. And that second one, flame, has been described as "the most complex malware ever found."
War is a big deal. You can't just rely on something meeting an old formal definition of "act of war"; to cause a war, there's got to be a risk of more damage (by some accounting) than we would do to ourselves by going to war.
Don't you remember Stuxnet? That is exactly what the us was doing! Surely it's been deniable, but who do you think did it?