Inadequately study national leader who’s affected by stoppages (9)

'affected by stoppages' is the definition.
The answer and definition can be both acts as well as being plural nouns.
Maybe they are linked in a way I don't understand?

'inadequately study national leader' is the wordplay.
I cannot really understand how this works, but
'study' could be 'do' (to 'do' a subject at university is to study it) and 'do' is found within the answer.
'national' could be 'n' (abbreviation listed in Chambers) and 'n' is found in the answer.
This explanation may well be incorrect...

'who's' is the link.

Can you help me to learn more?