Fighter helping movement of the people (9)
I believe the answer is:
migration
'movement of the people' is the definition.
(movement of people between countries)
'fighter helping' is the wordplay.
'fighter' becomes 'mig' (fighter jet produced by Russian company MiG).
'helping' becomes 'ration' (a ration is a serving or helping).
'mig'+'ration'='MIGRATION'
(Other definitions for migration that I've seen before include "The movement of people or animals from one locality to another" , "Wandering" , "Seasonal movement of animals or birds" , "Roaming it? (anagram)" , "Annual movement from one place to another" .)