Lethargy of good person up against soldiers (6)
I believe the answer is:
stupor
'lethargy' is the definition.
(thesaurus)
'good person up against soldiers' is the wordplay.
'good person' becomes 'st' (saint).
'against' means one lot of letters go next to another.
'soldiers' becomes 'or' (Other Rank).
'st'+'up'+'or'='STUPOR'
'of' acts as a link.
(Other definitions for stupor that I've seen before include "Proust found in dazed condition" , "Shocked or drunken state" , "mental dullness?" , "State of near insensibility" , "Dazed or unconscious condition, sometimes caused by alcohol" .)