Native Americans here — gosh, a soldier is retreating! (7)
I believe the answer is:
arapaho
'native americans here' is the definition.
(Native American tribe)
'gosh a soldier is retreating' is the wordplay.
'gosh' becomes 'oh' (both are expressions of shock).
'soldier' becomes 'para' (para is a kind of soldier).
'is retreating' says the letters should be written in reverse.
'oh'+'a'+'para'='ohapara'
'ohapara' back-to-front is 'ARAPAHO'.
(Other definitions for arapaho that I've seen before include "North American Indian" , "tribesman" , "North American native" , "Indians" , "tribe member" .)