The leaders of four states round America cause commotion (4)
I believe the answer is:
fuss
'cause commotion' is the definition.
'fuss' can be an answer for 'commotion' (fuss is a kind of commotion). I am not certain of the 'cause' bit.
'the leaders of four states round america' is the wordplay.
'the leaders of' suggests taking the first letters.
'round' indicates putting letters inside.
'america' becomes 'US' (United States).
The initial letters of 'four states' is 'fs'.
'fs' enclosing 'us' is 'FUSS'.
Can you help me to learn more?
(Other definitions for fuss that I've seen before include "Display of unnecessary interest" , "Protest -- excitement" , "Bustle and bother" , "(Show) excessive concern" , "Agitate" .)