Just hours after Israeli and US bombs started hitting Tehran on Saturday, Russia came out with a blunt statement, with the country's permanent representative to the UN, Vassily Nebenzia, calling it an "unprovoked act of armed aggression against a sovereign and independent UN member state." Moscow is one of Tehran's few but staunchest allies, and a possible collapse of the Iranian regime could be a blow for its geopolitical and economic interests. Then why has it not come to Tehran's rescue?