That's because Artsakh (Nagorno-Karabakh) is internationally recognized as being part of Azerbaijan. Even Armenia itself does not officially recognize the independence of Artsakh. Thus from a Russian point of view, Azerbaijani military attacks on Artsakh are an internal matter for the Azerbaijan government and not an act of aggression against Armenia proper which would trigger their mutual defense treaty.
During the war, both Armenian and Azerbaijani forces were doing a kind of kabuki dance, provoking the other side into bombarding either Armenia or Iran, to trigger either regional powers' intervention in the conflict.
It's a sad reality for the Armenian people that they were never truly independent and sovereign, but always a protectorate of the Iranians, Romans, Byzantines, Turks or Russians. I think everyone in Western leadership circles (or at least those who can actually place Armenia on a map) recognizes that and there is not the antagonism against them that, say, Belarus or to a lesser extent Serbia is experiencing.
Russia looked the other way because it was in the interest of Russia to look the other way. I believe the recent events in Ukraine have demonstrated that international law is held in pretty low regard. If Russia found it in their interest to intervene or prevent the war, they would have certainly done that. Instead, they chose to step away from one of their few allies/hostages.
Of course, but in this case they were technically in the clear, unlike Ukraine where one of the smartest things the Biden administration did was to preemptively blow the false flag operations that were being planned to justify the invasion.
The Azerbaijanis were certainly in close coordination with the Russians to establish what the Russian red lines were, and go right up to them, but no further.
During the war, both Armenian and Azerbaijani forces were doing a kind of kabuki dance, provoking the other side into bombarding either Armenia or Iran, to trigger either regional powers' intervention in the conflict.
It's a sad reality for the Armenian people that they were never truly independent and sovereign, but always a protectorate of the Iranians, Romans, Byzantines, Turks or Russians. I think everyone in Western leadership circles (or at least those who can actually place Armenia on a map) recognizes that and there is not the antagonism against them that, say, Belarus or to a lesser extent Serbia is experiencing.