Possible Clues:

• Letters near a hammer and sickle
• Khrushchev's home, in his native tongue
• 48-across, in 48-across
• Letters on some pre-1991 Olympic hockey jerseys
• Letters on an old Olympic jersey
• Cyrillic for USSR
• USSR, to Russians
• Letters on old Russian maps
• Initials on Yuri Gagarin's helmet
• Letters on some Olympic hockey jerseys, until 1991