Global struggle: virus from the east not treated (4,3)
I believe the answer is:
cold war
'global struggle' is the definition.
(global power struggle following World War Two)
'virus from the east not treated' is the wordplay.
'virus' becomes 'cold' (a cold is an infection or virus).
'from the east' says the letters should be written in reverse.
'not treated' becomes 'raw' (as in raw data).
'raw' back-to-front is 'war'.
'cold'+'war'='COLD WAR'
(Other definitions for cold war that I've seen before include "Conflict without engagement" , "Hostile period after 1945" , "Period of East-West political hostility" , "Low card (anag.)" , "East West tension" .)