Spain and Portugal and more than half of Russia is leaderless (6)
I believe the answer is:
iberia
'spain and portugal' is the definition.
(I've seen this before)
'more than half of russia is leaderless' is the wordplay.
I cannot really understand how this works, but
'is' could be 'be' and 'be' is located in the answer.
This explanation may well be incorrect...
'and' is the link.
Can you help me to learn more?
(Other definitions for iberia that I've seen before include "European countries" , "Spain and Portugal together" , "Spain/Portugal peninsula" , "Old name for Spanish peninsula" , "Mediterranean peninsula" .)