If people are not to, vaster redistribution is required (6)
I believe the answer is:
Here is my best explanation:
'if people are not' is the definition.
I can't judge whether this definition defines the answer.
'vaster redistribution is required' is the wordplay.
'redistribution is required' indicates anagramming the letters (letters must be redistributed to new positions).
'vaster' anagrammed gives 'STARVE'.
'to' acts as a link.
(Other definitions for starve that I've seen before include "Lack food", "Stop feeding", "Be without food", "Fail to take in", "Deprive of sustenance", "Averts (anag)", "Vaster (anag)", "Deprive of food", "Go without food" and "Suffer great hunger".)