Military command contemplates where armies clash (4,5)
I believe the answer is:
eyes front
'military command' is the definition.
(command to look ahead)
'contemplates where armies clash' is the wordplay.
'contemplates' becomes 'eyes' (eye can mean to contemplate or consider).
'where armies clash' becomes 'front' (eg a front in a war).
'eyes'+'front'='EYES FRONT'
(Other definitions for eyes front that I've seen before include "Military Command" , "Army order to look straight ahead" , "inspects line of battle" , "Look straight ahead - that's an order" .)