Red makes Military Intelligence come out (6)
I believe the answer is:
'red' is the definition.
(I've seen this before)
'military intelligence come out' is the wordplay.
'military intelligence' becomes 'MI' (as in MI5 or MI6 - British military intelligence).
'out' means one lot of letters goes inside another.
'mi' placed into 'come' is 'COMMIE'.
'makes' is the link.
(Other definitions for commie that I've seen before include "Red" , "Extreme left-winger" , "Eg, Marxist (colloq.)" , "Left wing" .)