Much ado about nothing in part of USSR (4)

I believe the answer is:

fuss

I'm a little stuck... Click here to teach me more about this clue!

'much ado about nothing in' is the definition.
I can't tell whether this definition defines the answer.

'part of ussr' is the wordplay.
'part' indicates a hidden word.
'FUSS' can be found hidden inside 'of ussr'.

Can you help me to learn more?

(Other definitions for fuss that I've seen before include "To-do" , "Commotion - worry" , "Bustle; ado" , "Unnecessary or excessive worry" , "trouble" .)

I've seen this clue in the Irish Times.

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