Which side has the firing-squad?
Am I right in thinking that the hero is in fact almost shot by the Whites -- who are nominally British allies! -- at the end of the film?
The others who are marched out to face the firing squad look more like Red partisans than Whites (especially the girl who grabs the gun), and I think that the Black Sea location (Odessa?) is introduced with a shot of the Tsarist double-eagle flag rather than the Communist banner... it would also explain the presence of the English-speaking hospital staff, and the favourable treatment of the Countess.
If this is the case, it's another of the picture's rather effective ironies; its strongest point is in its depiction of the mutual brutality of both sides.
Gather round, lads and lasses, gather round...