Bond’s assumption about supporting the Russian leaders (7)
I believe the answer is:
trammel
'bond's' is the definition.
(synonyms)
'assumption about supporting the russian leaders' is the wordplay.
'assumption' becomes 'lemma' (I can't justify this - if you can you should believe this answer much more).
'about' says the letters should be written backwards.
'supporting' means one lot of letters go next to another (in a down clue, some letters go below others).
'leaders' indicates taking the first letters.
The initial letters of 'the russian' is 'tr'.
'lemma' back-to-front is 'ammel'.
'ammel' after 'tr' is 'TRAMMEL'.
Can you help me to learn more?
(Other definitions for trammel that I've seen before include "Limit, hamper" , "bar" , "Hobble" , "Three-layered fishing net - melt ram (anag)" , "Place limits on" .)