Material for courses beginning to detail less visible military force (6,7)
I believe the answer is:
dinner service
'material for courses' is the definition.
(items for serving the courses of a meal)
'beginning to detail less visible military force' is the wordplay.
'beginning to' indicates taking the first letters.
'less visible' becomes 'inner' (as opposed to outer or superficial).
'military force' becomes 'service'.
The initial letter of 'detail' is 'd'.
'd'+'inner'+'service'='DINNER-SERVICE'
(Other definitions for dinner service that I've seen before include "Crockery for meal" , "Set" , "Plates and dishes for complete meal" , "Plates, dishes, etc" .)