Far back, it had to deal with the Luftwaffe (3)
I believe the answer is:
raf
'it had to deal with the luftwaffe' is the definition.
The definition suggests a singular noun which matches the answer.
'far back' is the wordplay.
'back' shows that the letters should be reversed in order.
'far' backwards is 'RAF'.
Can you help me to learn more?
(Other definitions for raf that I've seen before include "Airforce of Great Britain" , "Royal Air Force (abbr.)" , "It fought Battle of Britain" .)