American soldier in pub reasoned correctly (7)
I believe the answer is:
logical
'reasoned correctly' is the definition.
'american soldier in pub' is the wordplay.
'american soldier' becomes 'gi'.
'in' indicates putting letters inside.
'pub' becomes 'local' (I've seen this before).
'gi' put within 'local' is 'LOGICAL'.
(Other definitions for logical that I've seen before include "Sound" , "Well thought out" , "In accordance with reason" , "Clearly and soundly reasoned" , "Using reason" .)