Are in conflict with USA over one geographical area (7)
I believe the answer is:
eurasia
'geographical area' is the definition.
(I know that Eurasia is a type of geographical area)
'are in conflict with usa over one' is the wordplay.
'in conflict with' is an anagram indicator (letters clashing or in conflict with each other).
'over' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'are' mixed up with 'usa' gives 'eurasa'.
'eurasa' placed around 'i' is 'EURASIA'.
(Other definitions for eurasia that I've seen before include "Landmass extending west-east from Cape Roca to Cape Dezhnev" , "World's largest land mass" , "Large expanse of land" , "Unbroken landmass bearing two continents" , "Continental land mass" .)