Three peaks followed by a war film (4,4,4)

'war film' is the definition.
I don't know anything about this answer so I can't judge whether this works.

'three peaks followed by a' is the wordplay.
'three peaks' can mean three substitutions for 'peak'.
'peak' becomes 'tor' (a tor is a rocky peak).
'peak' becomes 'atora' (I can't explain this - if you can you should believe this answer much more).
'peak' becomes 'tor' (a tor is a rocky peak).
'followed by' is a charade indicator (letters next to each other).
'tor'+'atora'+'tor'+'a'='TORA TORA TORA'

Can you help me to learn more?