The most common and most likely answer to this crossword clue is the 4 plus 8 letter word OPEN CONFLICT
I've seen this crossword clue in The Daily Telegraph
O
P
E
N
C
O
N
F
L
I
C
T
Buddy explains!
The straight part
We know that "Yet it could be close combat" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case yet it could be close combat = open conflict.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.