Decree from football body leads to this whole argument (5)
I believe the answer is:
fatwa
'decree' is the definition.
(I have seen 'Islamic decree' mean 'fatwa' so perhaps 'decree' could also mean 'fatwa')
'football body leads to this whole argument' is the wordplay.
'football body' becomes 'FA'.
'leads to' indicates taking the first letters.
The first letters of 'this whole argument' is 'twa'.
'fa'+'twa'='FATWA'
'from' is the link.
(Other definitions for fatwa that I've seen before include "death sentence?" , "Legal ruling by Islamic religious leader" , "Islamic decree" , "Islamic opinion" , "Legal ruling by Islamic leader, as against Salman Rushdie" .)