End fuel crisis as required (7)
I believe the answer is:
needful
'required' is the definition.
(I know that required can be written as needful)
'end fuel crisis' is the wordplay.
'crisis' indicates an anagram.
'end'+'fuel'='endfuel'
'endfuel' with letters rearranged gives 'NEEDFUL'.
'as' acts as a link.
(Other definitions for needful that I've seen before include "Required" , "Poverty-stricken" , "Requisite, necessary" , "Nude elf (anag.)" , "poor" .)