Tolerate a twit giving an order to soldiers (5,2,4)
I believe the answer is:
stand at ease
'an order to soldiers' is the definition.
(I've seen this before)
'tolerate a twit' is the wordplay.
'tolerate' becomes 'stand' (synonyms).
'twit' becomes 'tease' (synonyms).
'stand'+'a'+'tease'='STAND AT EASE'
'giving' acts as a link.
(Other definitions for stand at ease that I've seen before include "An order to soldiers" , "Relax (on parade ground)" , "Assume a more relaxed position (military)" , "Command to soldiers" , "Instruction to soldiers - and sea state (anag)" .)