Nuclear mine exposed by soldier, essentially soldier leaving qualified (9)
I believe the answer is:
indelible
'essentially soldier leaving qualified' is the definition.
I can't judge whether this defines the answer.
'nuclear mine exposed by' is the wordplay.
'nuclear' becomes 'delible' (I can't justify this - if you can you should believe this answer much more).
'exposed' says to take the centre (outside letters removed).
'by' says to put letters next to each other.
The middle letters of 'mine' are 'in'.
'delible' put after 'in' is 'INDELIBLE'.
'soldier' is the link.
Can you help me to learn more?
(Other definitions for indelible that I've seen before include "not able to be forgotten" , "Of mark or stain, unable to be rubbed out" , "Of stain, unable to be removed" , "Permanent" , "fast" .)