With eccentrics about, miss what soldiers may do (5,5)
I believe the answer is:
close ranks
'with eccentrics' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'about miss what soldiers may do' is the wordplay.
I cannot really understand how this works, but
'about' could be 'c' (abbreviation for circa) and 'c' is found in the answer.
'miss' could be 'lose' (I've seen this in other clues) and 'lose' is found within the answer.
'soldiers' could be 'ranks' (rank can mean a group of soldiers in a line) and 'ranks' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for close ranks that I've seen before include "Display solidarity" , "make cabbies go out of business?" , "Unite in order to defend common interests" , "Unite as a defensive measure" , "to put taxi firms out of business?" .)