Attack Great Britain about importing Ritz-like crackers (10)
I believe the answer is:
blitzkrieg
'attack' is the definition.
(I have seen 'Sudden attack' mean 'blitzkrieg' so perhaps 'attack' could also mean 'blitzkrieg')
'great britain about importing ritz-like crackers' is the wordplay.
'great britain' becomes 'gb'.
'about' says the letters should be written backwards.
'importing' indicates putting letters inside.
'crackers' indicates anagramming the letters (informal term for mad).
'gb' back-to-front is 'bg'.
'ritz'+'like'='ritzlike'
'ritzlike' is an anagram of 'litzkrie'.
'bg' enclosing 'litzkrie' is 'BLITZKRIEG'.
(Other definitions for blitzkrieg that I've seen before include "Sudden overwhelming attack" , "Lightning war" , "Intense campaign" , "Sudden overpowering military attack" , "Sudden all-out offensive, aiming for quick victory" .)