Puzzle of vague image surrounding new leader (6)
I believe the answer is:
enigma
'puzzle' is the definition.
(thesaurus)
'vague image surrounding new leader' is the wordplay.
'vague' is an anagram indicator.
'surrounding' indicates putting letters inside.
'leader' says to take the initial letters.
The first letter of 'new' is 'n'.
'image' with letters rearranged gives 'eigma'.
'eigma' placed around 'n' is 'ENIGMA'.
'of' acts as a link.
(Other definitions for enigma that I've seen before include "Title of Elgar's set of variations" , "German military cipher machine" , "Something mysterious and puzzling" , "It's mysterious like gamine" , "Conundrum" .)