Smallest state broadcaster is likely to fail (5)
I believe the answer is:
risky
'likely to fail' is the definition.
(I've seen this in another clue)
'smallest state broadcaster' is the wordplay.
'smallest state' becomes 'RI' (Rhode Island is the smallest state in the USA).
'broadcaster' becomes 'sky' (Sky is a television company).
'ri'+'sky'='RISKY'
'is' is the link.
(Other definitions for risky that I've seen before include "Treacherous" , "Having possibility of danger or loss" , "Hazardous" , "taking a chance" , "Perilous" .)