You'd hope Putin is not so stupid as to start committing acts of war on US territory. Helping the Iranians against the US seems to have gone mostly unnoticed but I'm pretty sure that if such an act was traced back to russia there would be a different tune played soon after.
It’s being gong on for years in Europe. Nobody’s starting a war because they cut a fibre. Or burn down a telephone exchange. Or blow up a plane. Or kill a policeman, even if it can be attributed.
Salami tactics.