infrastructure and supplier base was lost.
indeed and ironically a large part was in Ukraine prior 1990.
For Iran , they got plenty of substitute aircraft from friendly Muslim countries ,some in South east Asia. , Cheap, until they broke down , then to the next ones, most paid in oil. Google earth Tehran Mehrabad airport north side to see where some of them are resting .
Russia could do the same .When there is money there is always a way.