It isn't a fight over nothing! (3,1,5)

'nothing' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'it isn't a fight over' is the wordplay.
I cannot quite see how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
'a' is within the answer.
'fight' could be 'scrap' (a scrap is a minor fight) and 'scrap' is located in the answer.
'over' could be 'o' (cricket abbreviation) and 'o' is found within the answer.
A single letter 'n' remains which might be clued in a way I don't see.
This explanation may well be incorrect...

Can you help me to learn more?