Criminal stuck without leader of cartel after trouble somewhere in Russia (7)
I believe the answer is:
irkutsk
'somewhere in russia' is the definition.
The definition suggests a singular noun which matches the answer.
'criminal stuck without leader of cartel after trouble' is the wordplay.
I cannot really understand how this works, but
'trouble' could be 'irk' (I've seen this in another clue) and 'irk' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for irkutsk that I've seen before include "Russian city" , "Principal city of Siberia -- UK skirt (anag)" .)