Appearance of soldiers capturing island (4)
I believe the answer is:
mien
'appearance' is the definition.
(thesaurus)
'soldiers capturing island' is the wordplay.
'soldiers' becomes 'men' (I've seen this before).
'capturing' indicates putting letters inside.
'island' becomes 'i'.
'men' going around 'i' is 'MIEN'.
'of' acts as a link.
(Other definitions for mien that I've seen before include "The carriage" , "A face - maybe mine" , "A manner like mine" , "Appearance, bearing" , "A face like mine" .)