I agree just to follow English military command (4,5)
I believe the answer is:
'military command' is the definition.
(I've seen this before)
'i agree just to follow english' is the wordplay.
'i agree' becomes 'yes' (both are affirmative answers).
'just' becomes 'right' (similar in meaning).
'to follow' says to put letters next to each other (some letters go after or follow others).
'english' becomes 'E' (abbreviation).
'yesright' after 'e' is 'EYES RIGHT'.
(Other definitions for eyes right that I've seen before include "Order" , "Military command" , "Look over there" .)