Answer: SSR

AnswerCrossword Clue
SSROld atlas letters
SSRUkr. or Est., once
SSRUkr., once, e.g.
SSRGeorgia, once (abbr.)
SSRCold War abbr.
SSRPre-1991 UKR or UZB
SSRLat. or Lith., once
SSRBelarus, in prev. days
SSRMoldova, formerly: abbr.
SSROld European map abbr.
SSRGeorgia, formerly: Abbr.
SSRUkr.'s old status
SSRFormer empire abbr.
SSRFormer world power div.
SSROld Communist letters
SSROld map initials
SSRUzbekistan, once: Abbr.
SSRKazakhstan, once: Abbr.
SSRLith., once
SSROld map letters
SSRCold War land: Abbr.
SSRLith., formerly
SSRLatvia, once (abbr.)
SSRUkr., once
SSRAzerbaijan, prev.
SSRLithuania, once: Abbr.
SSRBygone map letters
SSRUkr. or Lat., once
SSREstonia, once: Abbr.
SSRGeorgia, once: Abbr.
SSRKazakhstan, until 1991: Abbr.
SSRFormer Union member: Abbr.
SSRKazakhstan, once (abbr.)
SSRRuss. unit
SSRKazakh or Uzbek (abbr.)
SSRUkr. used to be one
SSRUkr., e.g., once
SSRUkr. or Lith., once
SSROld atlas abbr.
SSRUkr., formerly