Endlessly regret country embracing current collapse (9)
I believe the answer is:
ruination
'collapse' is the definition.
(I've seen this before)
'endlessly regret country embracing current' is the wordplay.
'endlessly' means to remove the last letter.
'regret' becomes 'rue' (to rue something is to regret it).
'country' becomes 'nation' (synonyms).
'embracing' is an insertion indicator.
'current' becomes 'I' (physics symbol).
'rue' with its final letter taken off is 'ru'.
'ru'+'nation'='runation'
'runation' enclosing 'i' is 'RUINATION'.
(Other definitions for ruination that I've seen before include "A fruit; Chuck ---, rock 'n' roll singer" , "Utter destruction" , "Crippling defeat" , "Complete downfall" , "In financial disaster" .)