A unit is obliged to retire as a result of a close combat but ends up with its back to uninhabitable terrain. The victor has a breakthrough and so a second round of close combat ensues. What happens if the same unit loses again but physically cannot retire further?
-Yahoo Group, 8/12/17
Per 6.3.2: "All retire movement must be used, unless the retiring Unit is blocked by uninhabitable terrain. If the path of retirement brings the Unit into contact with an enemy, the Unit immediately routs to the Reformation Area.”
So, in this case, a Unit is blocked between uninhabitable terrain and an enemy Unit, so after is performs all
the retire movement it can – which would be none – it is in contact with an enemy Unit, and therefore routs.
-David