BUR #14479 has been approved by @nonamethanks.
create alias red_army -> soviet_army
I think there are no significant difference between those tags. Was the red army intended to refer any military force of other communist/socialist countries beside the USSR? The wiki page of Red Army (21 posts) essentially shows no difference with Soviet Army (170 posts).
I think we should keep the tag Soviet Army which describes the ground forces.
Updated