Iron-clad, state such a conclusion? (8)
I believe the answer is:
foregone
'a conclusion?' is the definition.
(foregone conclusion is a kind of conclusion)
'iron-clad state' is the wordplay.
'iron' becomes 'fe' (Fe is the chemical symbol for iron).
'clad' is an insertion indicator.
'state' becomes 'oregon' (Oregon is an example**).
'fe' going around 'oregon' is 'FOREGONE'.
'such' acts as a link.
(Other definitions for foregone that I've seen before include "A conclusion may be this" , "Completed" , "A -- conclusion is an inevitable result" , "Eschewed" , "This conclusion was obvious in advance" .)