The most common and most likely answer to this crossword clue is the 6 letter word STALIN
S
T
A
L
I
N
More clues leading to the result STALIN
- Briefly follow popular Soviet leader
- Instal new, Communist leader
- Dictator nearly jaded at home
- Dictator’s blemish left hidden
- Soviet leader’s son to finish off story at home
- Moral taint engulfs sinister despot
- Part of pedestal inscribed for despot
- Old red mark, bit of lippy involved?
- European leader made his mark when about fifty
- Dictator of southern city in Estonia we hear
Buddy explains!

The straight part
We know that "Soviet leader" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case soviet leader = stalin.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.