Aid policy sees large extremity contract (4-5)
I believe the answer is:
lend-lease
'aid policy' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'large extremity contract' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'extremity' becomes 'end' (end is a kind of extremity).
'contract' becomes 'lease' (leasing is a kind of contracting).
'l'+'end'+'lease'='LEND-LEASE'
'sees' acts as a link.
Can you help me to learn more?
(Other definitions for lend-lease that I've seen before include "WWII arrangement; ladle seen (anag.)" , "US provision of military equipment to the UK and its allies in World War II" .)