I see men circling the opposition (7)
I believe the answer is:
enemies
'opposition' is the definition.
(I've seen this in another clue)
'i see men circling' is the wordplay.
'circling' indicates an anagram.
'i'+'see'+'men'='iseemen'
'iseemen' anagrammed gives 'ENEMIES'.
'the' is the link.
(Other definitions for enemies that I've seen before include "Those we fight" , "Foes, opponents" , "Foes, adversaries" , "Foes, hostile groups" .)