Subject of article: Middle East (5)
I believe the answer is:
theme
'subject' is the definition.
(I know that subject can be written as theme)
'article middle east' is the wordplay.
'article' becomes 'the' (the definite article in English).
'middle east' becomes 'me' (abbreviation for Middle East).
'the'+'me'='THEME'
'of' is the link.
(Other definitions for theme that I've seen before include "A subject or repeated melody" , "Musical idea; topic" , "notedly subject to variation" , "Melody on which variations are constructed" , "Subject matter, topic" .)