In fact, fairly young leaders are risky (4)
I believe the answer is:
iffy
'risky' is the definition.
(thesaurus)
'in fact fairly young leaders' is the wordplay.
'leaders' says to take the initial letters.
The initial letters of 'in fact fairly young' is 'IFFY'.
'are' acts as a link.
(Other definitions for iffy that I've seen before include "Dodgy" , "Informally dubious or uncertain" , "Sixth (RU) Nation" , "Chancy, suspect" , "Doubtful (colloq.)" .)