i guess when you lose an empire overnight reality takes a while to set in.
But from the Russian POV, the U.S. has been very active, militarily speaking, in the region since 2001. A conflict real close to their southern border, understandably, makes them nervous
It makes them nervous, but I'm not sure how "understandable" that is.
Russia is long enamored of conspiracy-theory beliefs involving the U.S. trying to "encircle" them and destroy their Russianness and suchlike, and those beliefs are rooted in paranoia. So, well, okay, I suppose the beliefs are indeed "understandable". I understand full well that Russia is arrogant, feels an imperialistic sense of entitlement towards her neighbors, and is paranoid regarding US intent. That's why the prospect of military action in Iran - a different country which has nothing to do with Russia - makes them "nervous". Yes, I do understand.