Nation in trouble, so thoughtless (7)
I believe the answer is:
lesotho
'nation' is the definition.
(Lesotho is an example)
'in trouble so thoughtless' is the wordplay.
'in' indicates the answer is hidden within the clue.
'LESOTHO' is hidden within 'trouble so thoughtless'.
(Other definitions for lesotho that I've seen before include "African country, formerly Basutoland" , "Independent kingdom, an enclave of South Africa" , "South African kingdom" , "Kingdom that was formerly Basutoland" , "Landlocked country in southern Africa" .)