Fear led to new form of government (7)
I believe the answer is:
federal
'form of government' is the definition.
(I've seen this before)
'fear led to new' is the wordplay.
'to new' is an anagram indicator.
'fear'+'led'='fearled'
'fearled' is an anagram of 'FEDERAL'.
(Other definitions for federal that I've seen before include "Common government for a group of normally autonomous states or regions" , "like the USA" , "Of the state" , "Of central government, not its separate states" , "Red flea (anag.)" .)