Former German state? American in Paris, confused (7)
I believe the answer is:
prussia
'former german state?' is the definition.
(I've seen this before)
'american in paris confused' is the wordplay.
'american' becomes 'us'.
'in' indicates putting letters inside.
'confused' indicates anagramming the letters.
'paris' with letters rearranged gives 'prsia'.
'us' inserted into 'prsia' is 'PRUSSIA'.
(Other definitions for prussia that I've seen before include "Old European state" , "old part of Europe" , "Former kingdom, included northern Germany and northern Poland" , "It fought France, Eighteen-seventy" , "Powerful pre-1871 state of central Europe" .)