Alleges Spain is hostile (6)
I believe the answer is:
averse
'hostile' is the definition.
(thesaurus)
'alleges spain' is the wordplay.
'alleges' becomes 'avers' ('aver' can be a synonym of 'allege').
'spain' becomes 'e' (abbreviation for Espana).
'avers'+'e'='AVERSE'
'is' is the link.
(Other definitions for averse that I've seen before include "Indisposed" , "Disinclined - sounds like a poem" , "A line of poetry is opposed" , "Antipathetic" , "Metal rod; card game" .)